Test 5

7. What will be the output of the program ?

#include<stdio.h>
 
int main()
{
    int x=30, *y, *z;
    y=&x; /* Assume address of x is 500 and integer is 4 byte size */
    z=y;
    *y++=*z++;
    x++;
    printf("x=%d, y=%d, z=%d\n", x, y, z);
    return 0;
}

• x=31, y=502, z=502
• x=31, y=500, z=500
• x=31, y=498, z=498
• x=31, y=504, z=504

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8. Which of the statements is correct about the program?

#include<stdio.h>
 
int main()
{
    int arr[3][3] = {1, 2, 3, 4};
    printf("%d\n", *(*(*(arr))));
    return 0;
}

• Output: Garbage value
• Output: 1
• Output: 3
• Error: Invalid indirection

Explanation ***arr (Third dereference):

• Here is the problem. You are now trying to apply the dereference operator (*) to the integer value 1.
• In C, you can only dereference pointers (memory addresses). You cannot dereference a plain integer.
• Because the operand is an int and not a pointer, the compiler throws an error: “Invalid indirection” (meaning you are trying to follow a pointer that isn’t there).

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11. Point out the error in the program?

#include<stdio.h>
#include<string.h>
void modify(struct emp*);
struct emp
{
    char name[20];
    int age;
};
int main()
{
    struct emp e = {"Sanjay", 35};
    modify(&e);
    printf("%s %d", e.name, e.age);
    return 0;
}
void modify(struct emp *p)
{
     p ->age=p->age+2;
}

• Error: in structure
• Error: in prototype declaration unknown struct emp
• No error
• None of above

Explanation The struct emp is mentioned in the prototype of the function modify() before declaring the structure.To solve this problem declare struct emp before the modify() prototype.

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12. 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;
}

• Error: invalid structure member in printf
• Error in this float category:5; statement
• No error
• 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.