Complicated Declarations - C Programming Questions and Answers

This set of C Multiple Choice Questions & Answers (MCQs) focuses on “Complicated Declarations – 1”.

Pre-requisite for C Complicated Declarations MCQ set: Video Tutorial on C Pointers.

1. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    void main()
```
```
    {
```
```
        struct student
```
```
        {
```
```
            int no;
```
```
            char name[20];
```
```
        };
```
```
        struct student s;
```
```
        no = 8;
```
```
        printf("%d", no);
```
```
    }
```

a) Nothing
b) Compile time error
c) Junk
d) 8
View Answer

Answer: b
Explanation: None.

2. What will be the output of the following C code?

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```
    #include <stdio.h>
```
```
    struct student
```
```
    {
```
```
        int no;
```
```
        char name[20];
```
```
    };
```
```
    void main()
```
```
    {
```
```
        struct student s;
```
```
        s.no = 8;
```
```
        printf("hello");
```
```
    }
```

a) Run time error
b) Nothing
c) hello
d) Varies
View Answer

Answer: c
Explanation: None.

3. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    struct student
```
```
    {
```
```
        int no = 5;
```
```
        char name[20];
```
```
    };
```
```
    void main()
```
```
    {
```
```
        struct student s;
```
```
        s.no = 8;
```
```
        printf("hello");
```
```
    }
```

a) Nothing
b) Compile time error
c) hello
d) Varies
View Answer

Answer: b
Explanation: None.

4. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    struct student
```
```
    {
```
```
        int no;
```
```
        char name[20];
```
```
    };
```
```
    void main()
```
```
    {
```
```
        student s;
```
```
        s.name = "hello";
```
```
        printf("hello");
```
```
    }
```

a) Nothing
b) hello
c) Compile time error
d) Varies
View Answer

Answer: c
Explanation: None.

5. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    void main()
```
```
    {
```
```
        struct student
```
```
        {
```
```
            int no;
```
```
            char name[20];
```
```
        };
```
```
        struct student s;
```
```
        s.no = 8;
```
```
        printf("%s", s.name);
```
```
    }
```

a) Nothing
b) Compile time error
c) Junk
d) 8
View Answer

Answer: c
Explanation: None.

6. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    struct student
```
```
    {
```
```
        int no;
```
```
        char name[20];
```
```
    };
```
```
    struct student s;
```
```
    void main()
```
```
    {
```
```
        s.no = 8;
```
```
        printf("%s", s.name);
```
```
    }
```

a) Nothing
b) Compile time error
c) Junk
d) 8
View Answer

Answer: a
Explanation: None.

7. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    int main()
```
```
    {
```
```
        int *((*x)())[2];
```
```
        x();
```
```
        printf("after x\n");
```
```
    }
```
```
    int *((*x)())[2]
```
```
    {
```
```
        int **str;
```

        str = (int*)malloc(sizeof(int)* 2);

```
        return str;
```
```
    }
```

a) Compile time error
b) Undefined behaviour
c) After x
d) None of the mentioned
View Answer

Answer: a
Explanation: None.

8. What will be the output of the following C code?

```
    #include <stdio.h>
```
```
    void (*(f)())(int, float);
```
```
    void (*(*x)())(int, float) = f;
```
```
    void ((*y)(int, float));
```
```
    void foo(int i, float f);
```
```
    int main()
```
```
    {
```
```
        y = x();
```
```
        y(1, 2);
```
```
    }
```
```
    void (*(f)())(int, float)
```
```
    {
```
```
        return foo;
```
```
    }
```
```
    void foo(int i, float f)
```
```
    {
```
```
        printf("%d %f\n", i, f);
```
```
    }
```

a) 1 2.000000
b) 1 2
c) Compile time error
d) Segmentation fault/code crash
View Answer

Answer: a
Explanation: None.

9. What does this declaration say?

int (*(*y)())[2];

a) y is pointer to the function which returns pointer to integer array
b) y is pointer to the function which returns array of pointers
c) y is function which returns function pointer which in turn returns pointer to integer array
d) y is function which returns array of integers
View Answer

Answer: a
Explanation: None.

10. What will be the output of the following C code?