C Programming Test And Answer 06

1.If malloc() successfully allocates memory it returns the number of bytes it has allocated.
A. True
B. False

Explanation:

Syntax: void *malloc(size_t size);

The malloc() function shall allocate unused space for an object whose size in bytes is specified by size and whose value is unspecified.

The order and contiguity of storage allocated by successive calls to malloc() is unspecified. The pointer returned if the allocation succeeds shall be suitably aligned so that it may be assigned to a pointer to any type of object and then used to access such an object in the space allocated (until the space is explicitly freed or reallocated). Each such allocation shall yield a pointer to an object disjoint from any other object. The pointer returned points to the start (lowest byte address) of the allocated space. If the space cannot be allocated, a null pointer shall be returned. If the size of the space requested is 0, the behavior is implementation-defined: the value returned shall be either a null pointer or a unique pointer.

2.Point out the error in the program?

#include<stdio.h>
int main()
{
    struct a
    {
        float category:5;
        char scheme:4;
    };
    printf("size=%d", sizeof(struct a));
    return 0;
}

A. Error: invalid structure member in printf
B. Error in this float category:5; statement
C. No error
D. None of above

Explanation:

Bit field type must be signed int or unsigned int.

The char type: char scheme:4; is also a valid statement.

3.What will be the output of the program ?

#include<stdio.h>
#include<string.h>
int main()
{
    char str[] = "India\0\BIX\0";
    printf("%s\n", str);
    return 0;
}

A. BIX
B. India
C. India BIX
D. India\0BIX

Explanation:

A string is a collection of characters terminated by ‘\0’.

Step 1: char str[] = “India\0\BIX\0”; The variable str is declared as an array of characters and initialized with value “India”

Step 2: printf("%s\n", str); It prints the value of the str.

The output of the program is “India”.