So it doesn't give any problem. operators in an integer constant expression shall only convert In int * const you have a constant pointer to . rev2023.6.2.43474. Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer variable ptrx. Copyright 2021 Quizack . The line char str = "IndiaBIX"; generates "Non portable pointer conversion" error. Find centralized, trusted content and collaborate around the technologies you use most. Step 1: const int x=5; The constant variable x is declared as an integer data type and initialized with value '5'. 5. 65535). Step 1: const int x=5; The constant variable x is declared as an integer data type and initialized with value '5'. It does make NUM_FOO a constant expression, and a later version of the language added constexpr for that purpose. Is there a place where adultery is a crime? int x = 5; int y; const int * const ptr = &x; printf("%d\n", *ptr); *ptr = 15; ptr = &y how many errors are in this coding segment ? Which functions can be used to set the file position indicator to the beginning of the file? 1. Step 4: *ptrx = 10; Here we are indirectly trying to change the value of the constant vaiable x. Step 2: printf("%d\n", i++); Here the variable 'i' is increemented by 1(one). Red Thing = "can't change the box it's next to" C's model of "constant expression" is closely tied to properties that allow translation units (source files) to be translated (compiled) independently to a form that requires no further high-level transformations to link. C. Reposition the file pointer to begining of that line. Here, Most of the Const questions are framed with Latest concepts, so that you may get updated through these Const Online tests. This means that int foo[NUM_FOO]; is a variable length array, defined as follows from section 6.7.6.2p4: If the size is not present, the array type is an incomplete type. Check out the latest interview questions and answers. #include, In which stage the following code : #include. 2. Thanks for contributing an answer to Stack Overflow! 576), AI/ML Tool examples part 3 - Title-Drafting Assistant, We are graduating the updated button styling for vote arrows. If you think the above answer is not correct, Please select a reason and add your answer below. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. the following code: int x = 5; int &refx = x; x, refx 5 int *ptrx = &x; Difference between declaring reference and 'address of' operator. Is there a legal reason that organizations often refuse to comment on an issue citing "ongoing litigation"? I thought C99 allowed variable size arrays anyway. Insufficient travel insurance to cover the massive medical expenses for a visitor to US? However, there is difference in pointers. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. They are both valid code and they are both equivalent. So, x = 10.If compiling with a C++ compiler, the above assignment is not allowed. The time you spent in Fresherslive will be the most beneficial one for you. What will be the output of the program? Get your news alert set up today, Once you confirm your Email subscription, you will be able to download Job Inteview Questions Ebook . You can extrapolate this to pointer to pointers, and the English may get confusing but the principle is the same. Step 3: char array[max]; This statement reports an error "constant expression required". What will be the output of the program? Preprocessor executes as a seperate pass before the execution of the compiler. What will be the output of the program?#include
int main(){ const char *s = ""; char str[] = "Hello"; s = str; while(*s) printf("%c", *s++); return 0;}. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. What will be the output of the program (myprog.c) given below if it is executed from the command line? Can I takeoff as VFR from class G with 2sm vis. for(i<=5 && i>=-1; ++i; i>0)
ProfileAnswers by bismitapadhyQuestions by bismitapadhy. Why would you use the keyword const if you already know variable should be constant? However, there's an exception that if you put it on the extreme left of the declaration, it applies to the first part of the type. Step 3: printf("%d\n", x); It prints the value of variable 'x'. GOODLUCK for Your Bright Future. Step 3: s = str; The value of the variable str is assigned to the variable s. Therefore str contains the text "Hello". "}; The variable str is declared as an pointer to the array of 6 strings. How are templates work so that the classes are properly generated by the compiler to work with both pointer types and non pointer types? Step 3: printf("%d, %d\n", c, d); The value of the variable 'c' and 'd' are printed. (C++ doesn't support VLAs. Step 1: int get(); This is the function prototype for the funtion get(), it tells the compiler returns an integer value and accept no parameters.Step 2: const int x = get(); The constant variable x is declared as an integer data type and initialized with the value "20".The function get() returns the value "20".Step 3: printf("%d", x); It prints the value of the variable x.Hence the output of the program is "20". #include int main() { const int x = 5; int *ptrx; ptrx = &x; *ptrx = x + *ptrx; printf("%d\n", x); return 0; }. Because, we cannot use variable to define the size of array. (C++ has different rules. Through Fresherslive Const questions and answers, you can acquire all the essential idea to solve any difficult questions on Const in short time and also in short cut method. Ans is 10const int x; means x is constant.We can't change value of x but we can chage *ptrx.But still we will get a warning suspecious pointer conversion. Paper. 2021 All rights reserved, What is the following program doing? operand to the sizeof or _Alignof operator. 9. I mean: As far as I know, const only get complex whenever it involves pointer. This above process will be repeated in Loop 3, Loop 4, Loop 5. When following a member function's parameter list, the const keyword specifies that the function doesn't modify the object for which it's . Copyright CuriousTab. What will be the output of the program? Practise through Fresherslive test series to ensure success in all competitive exams, entrance exams and placement tests. Declares a pointer whose data cannot be changed through the pointer: Declares a pointer who cannot be changed to point to something else: Yes, they are the same. For a pointer type though they are both valid code but not equivalent. Would sending audio fragments over a phone call be considered a form of cryptology? Input/output function prototypes and macros are defined in which header file? This will create an error "Cannot modify a const object".Because, we cannot modify a const variable. Report Error
Can I also say: 'ich tut mir leid' instead of 'es tut mir leid'? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. What will be the output of the program?#includeint main(){ const c = -11; const int d = 34; printf("%d, %dn", c, d); return 0;}, Step 1: const c = -11; The constant variable 'c' is declared and initialized to value "-11".Step 2: const int d = 34; The constant variable 'd' is declared as an integer and initialized to value '34'.Step 3: printf("%d, %dn", c, d); The value of the variable 'c' and 'd' are printed.Hence the output of the program is -11, 34, 2. Get invaluable Interview and Career Tips delivered directly to your inbox. What will be the output of the program?#include#includeunion employee{ char name[15]; int age; float salary;};const union employee e1;int main(){ strcpy(e1.name, "K"); printf("%s %d %f", e1.name, e1.age, e1.salary); return 0;}, The output will be (in 16-bit platform DOS):K 75 0.000000, 10. The rule in C++ is essentially that const applies to the type to its left. If there is any error while opening a file, fopen will return? In Germany, does an academia position after Phd has an age limit? D. Reposition the file pointer to begining of file. Winners are those who can use the simplest method for solving a question. Is there a reason beyond protection from potential corruption to restrict a minister's ability to personally relieve and appoint civil servants? Frees the specified navigation mesh object using the Detour allocator. Connect and share knowledge within a single location that is structured and easy to search. whose results are integer constants, _Alignof expressions, and Step 1: const int i=0; The constant variable 'i' is declared as an integer and initialized with value of '0'(zero). Not the answer you're looking for? even if that's IFR in the categorical outlooks? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. A constant expression is, roughly, one that can be evaluated at compile time (like 2+2 or 42 ). Const Questions with detailed description, explanation will help you to master the topic. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. What is the difference between const string & str and string const & str when passed as an argument to a function in c++. main() { const int x = 5; int *ptrx; &n This will result in an error. Please contact me if you there is any issue with the download. ptrx doesn't know, and doesn't need to know, that x is const (in fact a pointer object doesn't "know" anything), but the compiler is entitled to assume that, since you defined x as const, its value will never change. False, Always the macro is substituted by the given text/expression. typedef struct data mystruct; struct data { int x; mystruct *b; }; 'The expressions *ptr++ and ++*ptr are same'. Most of the job seekers finding it hard to clear Const test or get stuck on any particular question, our Const test sections will help you to success in Exams as well as Interviews. My C++ experience has made me internally deprecate #define as much as possible. Thus, there will be an error (invalid conversion from const int * to int * ). ptrx 0x7fff. Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer. To learn more, see our tips on writing great answers. Returns the minimum of two values. How to fix this loose spoke (and why/how is it broken)? Is "different coloured socks" not correct? #include int main() { const int x=5; const int *ptrx; ptrx=&x; *ptrx=10; printf("%d\n",x); return 0; }, Note: This Question is unanswered, help us to find answer for this one. This will result in an error.To change the value of const variable x we have to use *(int *)&x = 10; 8. Step 1: const int x=5; The constant variable x is declared as an integer data type and initialized with value '5'.Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer.Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer variable ptrx.Step 4: *ptrx = 10; Here we are indirectly trying to change the value of the constant vaiable x. How to vertical center a TikZ node within a text line? Yes, that is exactly the same. In int * const you have a constant pointer to an integer. Enabling a user to revert a hacked change in their email. 3. This will result in an error. Also at this point it increases i by one. Well, one is a constant integer and the other is an integer that's constant :-). So error, In C, it is ok, and i = 10; So dont use C compiler, it is time to use C++ compiler, just my one cent. Step 3:ptrx = &x;The address of the constant variablexis assigned to integer pointer variable ptrx. In this movie I see a strange cable for terminal connection, what kind of connection is this? const in C does not declare a compile-time constant. Interpretation, Submit
ungetc(c, stdin); "ungetc()" function pushes character 'a' back into input stream. For example, you can have in foo.c. What will be the output of the program? But as jamesdlin's answer pointed out, VS2019 doesn't support C99 or C11. Eg. char array[10]; or use macro char array[MAX]; Note: The above program will print A A as output in Unix platform. A variable with the const qualifier does not qualify as a constant expression. On top of the existing answers which are all good, the reason a const-qualified object fundamentally can't in general be a constant expression, in the sense of "one that can be evaluated at compile time" (as mentioned in Keith's answer), is that it can have external linkage. Building a safer community: Announcing our new Code of Conduct, Balancing a PhD program with a startup career (Ep. Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer. Those values clearly cannot be determined until execution time. A. Reposition the file pointer to a character reverse. The thing to remember (and yes, this is a bit counterintuitive) is that const doesn't mean constant. 10. Start your beginning, of anything you want by using our sample Const Online Test and create yourself a successful one. Thanks for contributing an answer to Stack Overflow! After sometime the stack memory will be filled completely. Men's response to women's teshuka - source and explanations. if talk to turbo compiler then run this program without error.and i m telling that turbo compiler has sevrak mistakes that confuse a begginer. Point out the error in the program? type. 3. However, this may not be enforced with some compilers.If compiling with a C compiler, there is a warning, but the assignment discards qualifier const. Step 1: const int x=5; The constant variable x is declared as an integer data type and initialized with value '5'. Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer. #include int main() { const int x = 5; int *ptrx; ptrx = &x; *ptrx = x + *ptrx; printf("%d\n", x); return 0; }. Step 1: const char *s = ""; The constant variable s is declared as an pointer to an array of characters type and initialized with an empty string.Step 2: char str[] = "Hello"; The variable str is declared as an array of charactrers type and initialized with a string "Hello".Step 3: s = str; The value of the variable str is assigned to the variable s. Therefore str contains the text "Hello".Step 4: while(*s){ printf("%c", *s++); } Here the while loop got executed untill the value of the variable s is available and it prints the each character of the variable s.Hence the output of the program is "Hello". shall only have operands that are integer constants, Step 2: const int x = get(); The constant variable x is declared as an integer data type and initialized with the value "20". Point out the error in the program (in Turbo-C). extern const int i; If you wish to define an extern variable in a C++ source code file for use in a C source code file, use: extern "C" const int x=10; to prevent name mangling by the C++ compiler. How to add a local CA authority on an air-gapped host of Debian. You can use an enum constant instead if you want to avoid using #define and want a symbolic name that can appear in a debugger. Code works in Python IDE but not in QGIS Python editor. So textual replacement of clrscr() to 100 occurs.The input program to compiler looks like this : Note: 100; is an executable statement but with no action. it is not a matter of compiler it is matter of our fundamental so fundamental is that we can not change constant .so there is error. If the size is VS2019, compiled with /TC. Correct Answer No error Explanation The output will be (in 16-bit platform DOS): K 75 0.000000 Constants problems Search Results 1. printf("%c", c); Now variable c = 'a'. Check out the latest current affairs questions and answers. Making statements based on opinion; back them up with references or personal experience. What will be the output of the program (in Turbo C)?#includeint fun(int *f){ *f = 10; return 0;}int main(){ const int arr[5] = {1, 2, 3, 4, 5}; printf("Before modification arr[3] = %d", arr[3]); fun(&arr[3]); printf("nAfter modification arr[3] = %d", arr[3]); return 0;}, Step 1: const int arr[5] = {1, 2, 3, 4, 5}; The constant variable arr is declared as an integer array and initialized toarr[0] = 1, arr[1] = 2, arr[2] = 3, arr[3] = 4, arr[4] = 5Step 2: printf("Before modification arr[3] = %d", arr[3]); It prints the value of arr[3] (ie. Manage Settings To avoid this error, we have to declare the size of an array as static. This will result in an error. This program will show an error "Cannot modify a const object". Example Consider the following code: int x = 5; int &refx = x; int *ptrx = &x; 5 Similar in syntax to the * in pointer declarations x, refx ptrx 0x7fff. Over vs runs -- same sequence number for each group. 6. Asking for help, clarification, or responding to other answers. Logical operator and pre-increment operator, Data from 1 column to be separated in multiple columns, Create package body with one priVATe subprogram only without package specification, How to use business process testing (bpt) with uft 12.02, Check if a number is divisible by another number using loop. This: const int NUM_FOO = 5; int foo[NUM_FOO]; is legal in both C99 and C++, but for different reasons.). an integer constant expression and the element type has a known Const Online Test questions are granted from basic level to complex level. C++ is not C.). Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer. Section 6.6p6 of the C11 standard regarding Constant Expressions states, An integer constant expression shall have integer type and Step 2: printf("%d, %d", sizeof(str), strlen(str[0])); sizeof(str) denotes 6 * 4 bytes = 24 bytes. Programming Questions & Answers : What would be the output of the following program ? Here the scanf("%c", &c); get the input from "stdin" because of "ungetc" function. ptry 0x7fff. What will be the output of the program? We and our partners use cookies to Store and/or access information on a device. Because we r using pointer to chane the value of the variable.So it should be ans is 10. if u give ptr=10 in above question then ans is 5 only, here an error because we can not convert const int * to int *. Effectively, this implies that the pointer shouldn't point to some other address. For example in int const * you have a pointer to a constant integer. @Hamish: some compilers accept all sorts of invalid code; the only way to be sure that something's valid is to look in the standard, or ask. I found that if always write const in right, it will becoming easier to read a complex pointer type, for fun. How to correctly use LazySubsets from Wolfram's Lazy package? The const type qualifier, even though its name is obviously derived from the English word "constant", really means "read-only". Should convert 'k' and 't' sounds to 'g' and 'd' sounds when they follow 's' in a word for pronunciation? Here we are trying tomodify the constant value of x to 10 which should not be done.. so it will pop an error saying that cant modify a constant value, actually there will be comiler warning.but the value will be changed when u run the program, Here we are assiging address of x to ptrx, so we are not changing, In C++, it is not allowed to convert const int* to int*. doesn't make NUM_FOO a constant expression. An increment_expression i>0 has no effect on value of i.so for loop get executed till the limit of integer (ie. However, there's an exception that if you put it on the extreme left of the declaration, it applies to the first part of the type. Answer: 10 x is a constant integer variable that holds the value 5. ptrx is a pointer variable that points to the address of x, What is the output of the following code? What will be output of following program and how? Why is this Pointer to Constant Pointer assignment Illegal? 2003-2023 Chegg Inc. All rights reserved. char *p; p = (char*) malloc(100); What is the following program doing? What does const do in this case - const int *ptr; Ask Question Asked 2 months ago Modified 2 months ago Viewed 73 times 2 I tested it here and can't tell that it does anything . char *strnset(char *s, int ch, size_t n); Sets the first n characters of s to ch, string before strnset: abcdefghijklmnopqrstuvwxyz, string after strnset: xxxxxxxxxxxxxnopqrstuvwxyz. scope; such arrays are nonetheless complete types. What will be the output of the program in TurboC?#includeint fun(int **ptr);int main(){ int i=10, j=20; const int *ptr = &i; printf(" i = %5X", ptr); printf(" ptr = %d", *ptr); ptr = &j; printf(" j = %5X", ptr); printf(" ptr = %d", *ptr); return 0;}, 7. Step 2: const int x=y; The constant variable 'x' is declared as an integer and it is initialized with the variable 'y' value. so expression i<=5 && i>=-1 initializes for loop. LOGIN to continue using GeekInterview website. I can change both the address it points to and the value at at that address. What will be the output of the program?#includeint fun(int **ptr);int main(){ int i=10; const int *ptr = &i; fun(&ptr); return 0;}int fun(int **ptr){ int j = 223; int *temp = &j; printf("Before changing ptr = %5xn", *ptr); const *ptr = temp; printf("After changing ptr = %5xn", *ptr); return 0;}, 9. the size is * instead of being an expression, the array type The function get() returns the value "20". initialized with value '5'. What is use of placing 'const' in range based for loop at diffrent places? Because the pointer occupies only 2 bytes. Computer Science Computer Science questions and answers What is the output of the following code? Experts are tested by Chegg as specialists in their subject area. printf("%c", c); prints the character 'a' which is given in the previous "scanf()" statement. I'm just adding a bit more context. Efficiently match all values of a vector in another vector. Two attempts of an if with an "and" are failing: if [ ] -a [ ] , if [[ && ]] Why? Connect and share knowledge within a single location that is structured and easy to search. In any case, a compiler is my first line of defense. Is there any philosophical theory behind the concept of object in computer science? Step 2:const int *ptrx;The constant variableptrxis declared as an integer pointer. What will be the output of the program?#includeint main(){ int y=128; const int x=y; printf("%dn", x); return 0;}, Step 1: int y=128; The variable 'y' is declared as an integer type and initialized to value "128".Step 2: const int x=y; The constant variable 'x' is declared as an integer and it is initialized with the variable 'y' value.Step 3: printf("%dn", x); It prints the value of variable 'x'.Hence the output of the program is "128". 1. For solving each and every question, very lucid explanations are provided with diagrams wherever necessary. typedef int *ptr; ptr p1,p2; In which stage the following code : #include gets replaced by the contents of the file stdio.h? 4).Step 3: fun(&arr[3]); The memory location of the arr[3] is passed to fun() and arr[3] value is modified to 10.A const variable can be indirectly modified by a pointer.Step 4: printf("After modification arr[3] = %d", arr[3]); It prints the value of arr[3] (ie. Cast Is Spider-Man the only Marvel character that has been represented as multiple non-human characters? 10 Const Questions and answers section with explanation for various online exam preparation, various interviews, C Language Const online test. 1. Is it possible for rockets to exist in a world that is only in the early stages of developing jet aircraft? Remember that const variable in principle can not be changed. Yes, they are the same. Evaluate your skill level in just 10 minutes with QUIZACK smart test system. Can anybody explain why the rejection occurs, since the compiler for sure knows at compile time the size of the array? 4 Answers Sorted by: 7 In C, this declaration: const int NUM_FOO = 5; doesn't make NUM_FOO a constant expression. Following code, the p2 is Integer pointer or Integer? *p dereferences it and so its value is H. Again & references it to an address and * dereferences it to the value H. printf( "%d..%d", sizeof(better), sizeof(best) ); The second pointer is of char type and not a good pointer. How to deal with "online" status competition at work? for(i=1; i<=5; i++) Here the for loop runs 5 times. See Answer Details of what constitutes a constant expression in C? Step 4: *ptrx = 10; Here we are indirectly trying to change the value of the constant vaiable x. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. How to fix this loose spoke (and why/how is it broken)? int x = 5, y = 0; int &refx = x; const int &ro_refx = x; int *ptry = &y; const int *ro_ptr1 = &y; int *const ro_ptr2 = &y; x, refx, 5 0x7fff. #include void main() { int x = 97; char y = x; printf("%cn", y); }, View Answer
To subscribe to this RSS feed, copy and paste this URL into your RSS reader. if(0.7 > a) here a is a float variable and 0.7 is a double constant. What will be the output of the program?#includeint main(){ const int x=5; const int *ptrx; ptrx = &x; *ptrx = 10; printf("%dn", x); return 0;}. Fresherslive provides most simplest methods to answer any tough questions. ro_ptr1 0x7fff. arithmetic types to integer types, except as part of an Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer variable ptrx. Does "int size = 10;" yield a constant expression? What will be the output of the program?#includeint get();int main(){ const int x = get(); printf("%d", x); return 0;}int get(){ return 20;}. What will be the output of the program? B. Reposition the file pointer stream to end of file. A header file contains macros, structure declaration and function prototypes. 576), AI/ML Tool examples part 3 - Title-Drafting Assistant, We are graduating the updated button styling for vote arrows. A macro must always be defined in capital letters. ro_ptr2 "Const pointer to an int" "Pointer to a const int" ro_refx Tip: Read the declaration "right-to-left" Legend Red Thing = "can't change the box it . Point out the error in the program? type; otherwise, the array type is a variable length array You'll get a detailed solution from a subject matter expert that helps you learn core concepts. 6. Please explain this 'Gift of Residue' section of a will. The pattern here becomes apparent if the definitions are. Is there a grammatical term to describe this usage of "may be"? I thought C had no more surprises for me, but this surprised me. Hence it prints '24'. Returns the maximum of two values. #include main() { FILE *stream=fopen('a.txt','r'); }. Split it with *. What will be the output of the program?#includeint main () { const c = -11; const int d = 34; printf ("%d, %dn", c, d); return 0;} error -11,34 11,34 none of these Workspace 2. & in type declaration is for reference declaration.Elsewhere it is 'address of' Legend What are some tradeoffs to using pointers vs references? printf( "%d..%d..%d", BLACK, BLUE, GREEN ); enum assigns numbers starting from 0, if not explicitly defined. Take it and make use of it to the fullest. To change the value ofconstvariablexwe have to use*(int *)&x = 10; Start typing & press "Enter" or "ESC" to close. Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer. How does a government that uses undead labor avoid perverse incentives? As for the error you're getting, that is because Visual Studio is not fully compliant with C99 and does not support variable length arrays. Which version of C is supported by VS2019 compiler? Step 1:const int x=5;The constant variablexis declared as an integer data type and initialized with value '5'. Legend Red Thing = "can't change Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. In for( i <= 5 && i >= -1; ++i; i>0) expression i<=5 && i>=-1 evaluates to one. const variables as constant expressions. Input/output function prototypes and macros are defined in which header file. rev2023.6.2.43474. constant size, the array type is not a variable length array The double constant 0.7 is greater than the float variable a. If you run the above code in Linux (32 bit platform), the output will be 24, 5 (because the size of pointer is 4 bytes). So this one was a real surprise. To change the value of const variable x we have to use *(int *)&x = 10; Step 1: A macro named MAX is defined with value 128. int *const is a constant pointer to integer This means that the variable being declared is a constant pointer pointing to an integer. const int *p vs. int const *p - Is const after the type acceptable? In Return of the King has there been any explanation for the role of the third eagle? Loop 1: Node classification with random labels for GNNs. So it prints the character 'a'. Was this answer useful? strlen(str[0])); becomes strlen(Frogs)). Continue with Recommended Cookies, https://quizack.com/c/mcq/output-of-following-program-include-stdio-h-int-main-const-int-x-5-const-int-ptrx-ptrx-x-ptrx-10-printf-d-n-x-return-0, What will be the output of following program? You'll get a detailed solution from a subject matter expert that helps you learn core concepts. it is not a matter of compiler it is matter of our fundamental so fundamental is that we can not change constant .so there is error. In July 2022, did China have more nuclear weapons than Domino's Pizza locations? Step 3: printf("%d", x); It prints the value of the variable x. And ` const int * const p = &someInt;` would give you a pointer that cannot be changed to a value that cannot be changed, if I'm not mistaken. only be used in declarations or type names with function prototype Error: unknown max in declaration/Constant expression required. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. In a macro call the control is passed to the macro. As for variable length arrays, yes, C added them in C99 (and made them optional in C11). Electronics and Communication Engineering. Step 2: const int max=128; The constant variable max is declared as an integer data type and it is initialized with value 128. Copyright 2014-2023 GeekInterview.com | All Rights Reserved. To change the value of const variable x we have to use *(int *)&x = 10; Step 2: const int d = 34; The constant variable 'd' is declared as an integer and initialized to value '34'. What is the exact meaning of "int const* " in C? 5. const keyword and constant expressions in C99 and C11. Once you realise the "normal" form of putting the, Building a safer community: Announcing our new Code of Conduct, Balancing a PhD program with a startup career (Ep. scanf("%c", &c); Here we give 'a' as input. Hence the output of the program is -11, 34. Two attempts of an if with an "and" are failing: if [ ] -a [ ] , if [[ && ]] Why? The thing to remember (and yes, this is a bit counterintuitive) is that const doesn't mean constant. Each question carries 1 mark; there are no negative marks. Why is const int x = 5; not a constant expression in C? Const qualifier doesn't affect the value of integer in this scenario so the value being stored in the address is allowed to change. True, the header file contains classes, function prototypes, structure declaration, macros. What will be the output of the program?#includeint main(){ const int i=0; printf("%dn", i++); return 0;}. if talk to turbo compiler then run this program without error.and i m telling that turbo compiler has sevral mistakes that confuse a begginers. C syntax reads crappy no matter what you do. Which of the following function sets first n characters of a string to a given character? True (but C++ does allow this when the initial value is visible; I'm not sure of the exact rules). This will create an error "Cannot modify a const object". To acquire clear understanding of Const, exercise these advanced Const questions with answers. Copyright 2019 Sawaal.com | All Rights Reserved. If What will be the output of the program? #include<stdio.h> int main () { const char *s = ""; char str [] = "Hello"; s = str; while (*s) printf ("%c", *s++); return 0; } Options A. Frees the specified query object using the Detour allocator. const int x; means x is constant.We can't change value of x but we can chage *ptrx. Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer variable ptrx. How does the number of CMB photons vary with time? Does substituting electrons with muons change the atomic shell configuration? If the size of pointer is 4 bytes then What will be the output of the program ? Asking for help, clarification, or responding to other answers. variable ptrx. 7. int main(){ const int x=5; const int *ptrx; ptrx = &x; *ptrx = 10; printf("%d\n", x); return 0;}. For another dicussion on the merits of doing one over the other, see my question on the subject. The consent submitted will only be used for data processing originating from this website. Word to describe someone who is ignorant of societal problems. Discuss, #include void main() { int y = 3; int x = 5 % 2 * 3 / 2; printf("Value of x is %d", x); }, #include void main() { int x = 1, z = 3; int y = x << 3; printf( "%dn", y ); }, Compiler error: Undefined label 'here' in function main, * is a dereference operator & is a reference operator. In this example, the value of NUM_FOO cannot be known when compiling bar.c; it is not known until you choose to link foo.o and bar.o. So that they have enough time for solving all the questions in examination, correctly without any tense. The output will be (in 16-bit platform DOS): Step 2: char str[] = "Hello"; The variable str is declared as an array of charactrers type and initialized with a string "Hello". What will be the output of the program in TurboC? Which functions can be used to set the file position indicator to the beginning of the file? You're Welcome to use the Fresherslive Online Test at any time you want. 10).Hence the output of the program isBefore modification arr[3] = 4After modification arr[3] = 10, 4. This is also why you can't use addresses in constant expressions except for address constant expressions which are limited to essentially the address of an object plus a constant. Can you combine the following two statements into one? We reviewed their content and use your feedback to keep the quality high. What control inputs to make if a wing falls off? Men's response to women's teshuka - source and explanations. To eliminate the error, we have to change the above line to. Which standard library function will you use to find the last occurance of a character in a string in C? Defining constant in c with const keyword, C constant expressions. Time Management for answering the Const questions quickly is foremost important for success in Competitive Exams and Placement Interviews. However, VS2019 does not support C99. Yes, too many recursive calls may result into stack overflow. floating constants that are the immediate operands of casts. Is it not the case that C99 allows variable size arrays? Because, we cannot modify a const variable. A constant expression is, roughly, one that can be evaluated at compile time (like 2+2 or 42). Step 3: ptrx = &x; The address of the constant variable x is assigned to integer pointer variable ptrx. typedef struct data mystruct; struct data { int x; mystruct *b; }; 'The expressions *ptr++ and ++*ptr are same' Which is a correct way to initialize an array? Just get into the habit to write, You should also include 'int const *' and just for a laugh 'int const * const', @Cogwheel - Precisely. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Error B. H C. Hello D. Hel They can be applied any number of times provided it is meaningful. The rule in C++ is essentially that const applies to the type to its left. expression i>0 is the increment expression. But still we will get a warning suspecious pointer conversion. I would not want to use such compiler then. In the printf call, the compiler undoubtedly generated code to load a literal value 5 rather than loading the current value of x. Deallocates a memory block. Is it true that too many recursive calls may result into stack overflow? char *str = "IndiaBIX"; (or) char str[] = "IndiaBIX"; Step 1: char *str[] = {"Frogs", "Do", "Not", "Die", "They", "Croak! I am unable to determine why this C program gives me this answer. Step 2: const int *ptrx; The constant variable ptrx is declared as an integer pointer. Hence stack overflow error will occur. Const questions are delivered with accurate answer. expression ++i is the loop condition. Here p points to the first character in the string "Hello". An example of data being processed may be a unique identifier stored in a cookie. You just have to learn the rules. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Why do some images depict the same constellations differently? Are you seeking for good platform for practicing Const questions in online. How can an accidental cat scratch break skin but not damage clothes? C99 does support VLAs. because when a function is called its return address is stored in stack. Consider, for example, that these are a perfectly valid declarations: The const just means that you can't modify the value of r or now after they've been initialized. Data
Which is a correct way to initialize an array? I have an idea how to interpret (non)const pointers and data. How to join two one dimension lists as columns in a matrix. What will be the output of the program, if a, Which of the following statements are correct about an. This is the right place. What would be the output of the following program ? Before modification arr[3] = 4 After modification arr[3] = 10, Error: cannot convert parameter 1 from 'const int **' to 'int **', Synthesis of sentences (make into one sentence). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. What will be the output of the program?#include<stdio.h>int main () { const int i=0; printf ("%dn", i++); return 0;} 10 11 no output Error: ++needs a value Workspace 3. Loop condition always get evaluated to true. @ T.E.D. Not the answer you're looking for? Note that const qualified integer objects are not included. is a variable length array type of unspecified size, which can Why cannot a const struct field be used as an initializer in C? Does the policy change for AI-generated content affect users who (want to) What is the difference between const double and double const? #include int main () { const int x = 5; int *ptrx; ptrx = &x; *ptrx = x + *ptrx; printf ("%d\n", x); return 0; } This problem has been solved! Step 1: const int x=5; The constant variable x is declared as an integer data type and initialized with value '5'. Developers & technologists worldwide first character in a world that is only the... Max in declaration/Constant expression required '' third eagle Personalised ads and content measurement, audience insights and product.. Ptrx ; the constant variable ptrx is declared as an integer pointer coworkers, Reach developers technologists. Online exam preparation, various interviews, C added them in C99 and.. Corruption to restrict a minister 's ability to personally relieve and appoint servants! That the pointer shouldn & # x27 ;: - ) initialize an array determined until execution.. Write const in C CC BY-SA occurance of a character reverse to the. If talk to turbo compiler has sevrak mistakes that confuse a begginer of an array static! Constant expression in C by Chegg as specialists in their subject area expressions in C99 ( yes! Medical expenses for a visitor to US values clearly can not use variable to define the size is VS2019 compiled! The string `` Hello '' and create yourself a successful one step 2: const int * const you a... Size of pointer is 4 bytes then what will be repeated in 3... Be an error ( invalid conversion from const int x = 5 ; int * p - is const the... Apparent if the size of pointer is 4 bytes then what will be the output of the program! Max ] ; this statement reports an error, in which header file contains classes, function prototypes macros! Made me internally deprecate # define as much as possible Lazy package without error.and i m that... Executed till the limit of integer ( ie, https const int x=5 const int *ptrx //quizack.com/c/mcq/output-of-following-program-include-stdio-h-int-main-const-int-x-5-const-int-ptrx-ptrx-x-ptrx-10-printf-d-n-x-return-0, what be. A minister 's ability to personally relieve and appoint civil servants your as... Str = `` IndiaBIX '' ; generates `` non portable pointer conversion = 5 ; int * ptrx the... ( and made them optional in C11 ) any philosophical theory behind the of. Eliminate the error in the program to find the last occurance of a string a. To an integer constant expression required those who can use the simplest method for solving a question b. the! Match all values of a character reverse within a single location that is structured and easy to search statements. To personally relieve and appoint civil servants the initial value is visible i... In this movie i see a strange cable for terminal connection, kind... -- same sequence number for each group our sample const Online test at any time you by... The atomic shell configuration a world that is structured and easy to search site /. By one a complex pointer type, for fun str = `` IndiaBIX ;... Declaration/Constant expression required code works in Python IDE but not damage clothes to its left a. First n characters of a string to a constant expression required define the size of array its.... Non ) const pointers and data ad and content, ad and content, ad and content, and! Call be considered a form of cryptology ad and content measurement, audience insights and development. Always write const in C principle can not modify a const variable in principle can not use to! Type has a known const Online test and create yourself a successful one some of our use!, please select a reason beyond protection from potential corruption to restrict a minister 's ability personally... `` int const * `` in C with const keyword, C constant expressions in C99 ( yes! Program doing the updated button styling for vote arrows for GNNs p ; p = ( *. Error ( invalid conversion from const int * to int * ) const questions in examination, correctly any! For data processing originating from this website local CA authority on an issue citing `` ongoing ''! A character in a cookie expression required '' third eagle code works Python. Inputs to make if a, which of the following program and how will help to... C99 and C11 both equivalent stage the following program doing found that if always write in! Content measurement, audience insights and product development int x = 5 not... Personally relieve and appoint civil servants program and how n't support C99 or C11 this.. For variable length arrays, yes, C constant expressions in C99 ( and made them optional C11... Have a pointer to a character reverse falls off found that if always write const in right, it becoming... Get confusing but the principle is the difference between const string & str and string const str! Response to women 's teshuka - source and explanations skin but not in QGIS Python editor atomic. Non pointer types and non pointer types and non pointer types statements are correct about an success competitive... For AI-generated content affect users who ( want to use such compiler then under CC.. The type to its left occurance of a character in a macro call the control is to. Str is declared as an pointer to begining of file in Germany, does an academia position after has... & # x27 ; ll get a detailed const int x=5 const int *ptrx from a subject expert! Be repeated in loop 3, loop 5 node within a single that... Sevrak mistakes that confuse a begginer with both pointer types and non pointer types reports an error ( invalid from... Can i also say: 'ich tut mir leid ' instead of tut. Carries 1 mark ; there are no negative marks is not correct, please select a reason beyond from! With time `` non portable pointer conversion after Phd has an age limit a compile-time constant who ( to... Operators in an integer pointer x ) ; } bit counterintuitive ) is that const variable convert in const... = & x ; the address of the constant variable x is assigned to integer pointer questions. To set the file pointer to constant pointer to an integer constant and. Conduct, Balancing a Phd program with a startup Career ( Ep, 34 the exact meaning of `` const... In an integer pointer be defined in which header file contains macros, declaration. The above answer is not allowed position indicator to the type to its left % C '', & ). From this website exams and placement tests, structure declaration and function prototypes and macros are defined in which file. Updated through these const Online test both valid code but not equivalent for you show an error LazySubsets Wolfram. Occurance of a string to a character in the string `` Hello '' function in C++ main ( ) const! To set the file pointer stream to end of file are correct about an just minutes... X=5 ; the constant variableptrxis declared as an integer pointer class G with 2sm vis provided it is from. X but we can not modify a const variable in principle can modify... Turbo compiler has sevral mistakes that confuse a begginers this point it increases by... Immediate operands of casts function will you const int x=5 const int *ptrx the keyword const if think... The simplest method for solving all the questions in examination, correctly any! Many recursive calls may result into stack overflow crappy no matter what do. For a pointer type, for fun specified navigation mesh object using the allocator... Initialize an array theory behind the concept of object in computer Science ;. - source and explanations ( invalid conversion from const int * ptrx comment on an host..., explanation will help you to master the topic function will you use most string C... Type is not allowed or personal experience that helps you learn core concepts say: 'ich mir. A begginers it broken ) test system difference between const string & str and string const & str and const... Matter expert that helps you learn core concepts language const Online test at any time you by! Subject area with QUIZACK smart test system what is the difference between const double and double const sending audio over... Societal problems runs -- same sequence number for each group on writing great answers i... I < =5 & & i > =-1 initializes for loop at diffrent places a const.. Any number of times provided it is meaningful Reposition the file position indicator to the.... What constitutes a constant expression in C how are templates work so that they enough... Insights and product development match all values of a will a part of their legitimate business without! R ' ) ; what is use of it to the beginning of the variable. Avoid perverse incentives to const int x=5 const int *ptrx a hacked change in their email C++,! =5 ; i++ ) here a is a constant expression, and the other, see question. Preprocessor executes as a part of their legitimate business interest without asking for consent Management for answering the qualifier... 5. const keyword and constant expressions in C99 and C11 detailed solution from a subject expert. Url into your RSS reader ( i < =5 ; i++ ) here a is a float a! I=1 ; i 'm not sure of the language added constexpr for that purpose, where developers & worldwide... No negative marks C '', & C ) ; it prints the value the! Change in their subject area i.so for loop runs 5 times internally deprecate # define as much possible! Other, see our Tips on writing great answers, since the compiler to work with both pointer types non..., macros in July 2022, did China have more nuclear weapons than Domino 's Pizza?... Have to change the value of the program find the last occurance of a vector in another vector ' input. ; becomes strlen ( Frogs ) ), audience insights and product development loose spoke ( and why/how is broken!
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