C Programming - Library Functions

1. 

Is standard library a part of C language?

A. Yes
B. No

Answer: Option B

Explanation:

The C standard library consists of a set of sections of the ISO C standard which describe a collection of header files and library routines used to implement common operations, such as input/output and string handling, in the C programming language. The C standard library is an interface standard described by a document; it is not an actual library of software routines available for linkage to C programs.

2. 

Will the program outputs "IndiaBIX.com"?

#include<stdio.h>
#include<string.h>

int main()
{
    char str1[] = "IndiaBIX.com";
    char str2[20];
    strncpy(str2, str1, 8);
    printf("%s", str2);
    return 0;
}

A. Yes
B. No

Answer: Option B

Explanation:

No. It will print something like 'IndiaBIX(some garbage values here)' .

Because after copying the first 8 characters of source string into target string strncpy() doesn't terminate the target string with a '\0'. So it may print some garbage values along with IndiaBIX.


3. 

The itoa function can convert an integer in decimal, octal or hexadecimal form to a string.

A. Yes
B. No

Answer: Option A

Explanation:

itoa() takes the integer input value input and converts it to a number in base radix. The resulting number a sequence of base-radix digits.

Example:


/* itoa() example */
#include <stdio.h>
#include <stdlib.h>

int main ()
{
	int no;
	char buff [50];
	printf ("Enter number: ");
	scanf ("%d",&no);
    
	itoa (no,buff,10);
	printf ("Decimal: %s\n",buff);
    
	itoa (no,buff,2);
	printf ("Binary: %s\n",buff);
    
	itoa (no,buff,16);
	printf ("Hexadecimal: %s\n",buff);
    
	return 0;
}

Output:
Enter a number: 1250
Decimal: 1250
Binary: 10011100010
Hexadecimal: 4e2


4. 

The prototypes of all standard library string functions are declared in the file string.h.

A. Yes
B. No

Answer: Option A

Explanation:

string.h is the header in the C standard library for the C programming language which contains macro definitions, constants, and declarations of functions and types used not only for string handling but also various memory handling functions.

5. 

scanf() or atoi() function can be used to convert a string like "436" in to integer.

A. Yes
B. No

Answer: Option A

Explanation:

scanf is a function that reads data with specified format from a given string stream source.
scanf("%d",&number);

atoi() convert string to integer.
var number;
number = atoi("string");