Standard Library Functions — Part 1 MCQs with Explanations

strlen() is the correct answer to “Which standard library function is used to calculate the length of a string in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

To print formatted text to the standard output is the correct answer to “What is the purpose of the 'printf' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

math.h is the correct answer to “Which library should be included to use the 'sqrt' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Compares two strings and returns an integer indicating their relationship is the correct answer to “What does the 'strcmp' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

A random integer is the correct answer to “What is the return value of the 'rand' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

rand() is the correct answer to “Which function is used to generate a random number in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Converts a string to an integer is the correct answer to “What is the purpose of the 'atoi' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

math.h is the correct answer to “Which library should be included to use the 'sin' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Reads a line of text from a file is the correct answer to “What does the 'fgets' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

fopen() is the correct answer to “Which function is used to open a file in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

To calculate the absolute value of an integer is the correct answer to “What is the purpose of the 'abs' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

fflush() is the correct answer to “Which standard library function is used to clear the standard input buffer in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Copies one string to another is the correct answer to “What does the 'strcpy' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

ceil() is the correct answer to “Which function is used to find the smallest integer greater than or equal to a given floating-point number in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Copies one string to another is the correct answer to “What is the purpose of the 'strcpy' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

math.h is the correct answer to “Which library should be included to use the 'pow' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Concatenates two strings is the correct answer to “What does the 'strcat' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

floor() is the correct answer to “Which standard library function is used to find the largest integer less than or equal to a given floating-point number in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Converts a character to lowercase is the correct answer to “What is the purpose of the 'tolower' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

The character read from the standard input is the correct answer to “What is the return value of the 'getchar' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Reads a character from the standard input without echoing is the correct answer to “What does the 'getch' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

sqrt() is the correct answer to “Which function is used to find the square root of a number in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Checks if a character is alphabetic is the correct answer to “What is the purpose of the 'isalpha' function in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

fopen() is the correct answer to “Which standard library function is used to open a file in C”. This question is standard in competitive examination syllabi for Standard Library Functions.

Calculates the absolute value of an integer is the correct answer to “What does the 'abs' function in C do”. This question is standard in competitive examination syllabi for Standard Library Functions.

va_arg is the correct answer to “The C library macro type . . . . . . . . retrieves the next argument in the parameter list of the function with type.”. This question is standard in competitive examination syllabi for Standard Library Functions.

123456 123456 is the correct answer to “What will be the output of the following C code? char str[20]; strcpy(str, "123456"); res = atoi(str); printf("%s %d\n", str, res);”. This question is standard in competitive examination syllabi for Standard Library Functions.

false is the correct answer to “MB_CUR_MAX is not defined in stdlib.h.”. This question is standard in competitive examination syllabi for Standard Library Functions.

sig_atomic_t is the correct answer to “What is the type declared by the header file signal.h”. This question is standard in competitive examination syllabi for Standard Library Functions.

_ _FILE_ _ and _ _LINE_ _ is the correct answer to “The source filename and line number come from the preprocessor macros . . . . . . . . and . . . . . . . .”. This question is standard in competitive examination syllabi for Standard Library Functions.

determine length of next multibyte code is the correct answer to “What will the given C code do? #include <stdlib.h> _Mbsave_Mbxlen={0}; int (mblen)(const char *s ,size_t n) { return(_Mbtowc(NULL s,n,&_Mbxlen)); }”. This question is standard in competitive examination syllabi for Standard Library Functions.

The atexit() function is used to return zero if the registration succeeds, nonzero if it fails is the correct answer to “Which of the given statement is true with respect to the function atexit()”. This question is standard in competitive examination syllabi for Standard Library Functions.

prints assertion message and aborts is the correct answer to “What will be the output of the following C code? #include <assert. h> #include <stdio . h> #include <stdlib.h> void -Assert (char *mesg) { fputs (mesg, stderr); fputs (" -- assertion failed\n" , stderr); abort () ; }”. This question is standard in competitive examination syllabi for Standard Library Functions.

the function where setjmp() was called has terminated, then the results are undefined is the correct answer to “Which is the true statement with respect to the function longjmp()”. This question is standard in competitive examination syllabi for Standard Library Functions.

signal.h is the correct answer to “Which among the given header file is used to handle different signals reported during program execution”. This question is standard in competitive examination syllabi for Standard Library Functions.

bsearch() is the correct answer to “Which of the given function is used for searching”. This question is standard in competitive examination syllabi for Standard Library Functions.

clock ticks is the correct answer to “The library function clock() returns the number of . . . . . . . . elapsed since the start of the program.”. This question is standard in competitive examination syllabi for Standard Library Functions.

cosh(x) is the correct answer to “Which of the given C function can be used instead of the apparent identity pointed to by y? int x=1; double y= 0.5 * (exp (x) + exp (-x));”. This question is standard in competitive examination syllabi for Standard Library Functions.

malloc() does not set the memory to zero whereas calloc() sets allocated memory to zero is the correct answer to “Select the right statement with reference to malloc() and calloc().”. This question is standard in competitive examination syllabi for Standard Library Functions.

void assert(int expression) is the correct answer to “Which is the correct declaration of macro assert”. This question is standard in competitive examination syllabi for Standard Library Functions.