Structure And Union — Part 1 MCQs with Explanations

You cannot initialize members in structure declaration.

As all the ways are legal and valid.

Solution: 2

As we cannot create a variable of itself as a member of the structure, but a reference can be created to create a self referential structure.

As all the members shares the same memory.

In this code, the variable q is declared but not initialized. When you try to use strcpy function to copy the value of p.name to q.name , you are accessing memory that has not been allocated for q.name , which leads to undefined behavior. This undefined behavior could result in a segmentation fault or a code crash. Therefore, the correct answer is Option B: Segmentation fault/code crash.

struct is the correct answer to “What is the keyword used to define a structure in C”. This question is standard in competitive examination syllabi for Structure And Union.

Variables is the correct answer to “In a structure, what are the members also known as”. This question is standard in competitive examination syllabi for Structure And Union.

Another structure is the correct answer to “Which of the following can be a member of a structure”. This question is standard in competitive examination syllabi for Structure And Union.

. (dot) is the correct answer to “How do you access a member of a structure in C”. This question is standard in competitive examination syllabi for Structure And Union.

Union allows only one active member is the correct answer to “What is the primary difference between a structure and a union in C”. This question is standard in competitive examination syllabi for Structure And Union.

By the size of its largest member is the correct answer to “How is the size of a structure determined in C”. This question is standard in competitive examination syllabi for Structure And Union.

struct Person { char* name; int age; } is the correct answer to “Which statement correctly defines a structure named "Person" with members "name" and "age" of type char* and int respectively”. This question is standard in competitive examination syllabi for Structure And Union.

Size of the largest member is the correct answer to “What does the 'sizeof' operator in C return for a union”. This question is standard in competitive examination syllabi for Structure And Union.

Yes, without any limitations is the correct answer to “Can a structure have another structure as a member in C”. This question is standard in competitive examination syllabi for Structure And Union.

. (dot) is the correct answer to “Which operator is used to access a union member when the union is a part of a structure”. This question is standard in competitive examination syllabi for Structure And Union.

It leads to undefined behavior is the correct answer to “What happens when you assign a value to one member of a union and then access another member in C”. This question is standard in competitive examination syllabi for Structure And Union.

struct is the correct answer to “Which keyword is used to define an anonymous structure or union within another structure or union”. This question is standard in competitive examination syllabi for Structure And Union.

Only the first assigned member is the correct answer to “In a union, which member can you access safely after assigning a value to one of its members”. This question is standard in competitive examination syllabi for Structure And Union.

union is the correct answer to “Which type of variable should you use if you want to store different types of data at different times within the same memory location”. This question is standard in competitive examination syllabi for Structure And Union.

Structures allocate memory for the largest member is the correct answer to “Which of the following is true about the memory allocation of structures and unions in C”. This question is standard in competitive examination syllabi for Structure And Union.

Yes, by reference is the correct answer to “In C, can a structure be passed as an argument to a function”. This question is standard in competitive examination syllabi for Structure And Union.

To create a new data type name for the structure or union is the correct answer to “What is the purpose of using a typedef with structures and unions in C”. This question is standard in competitive examination syllabi for Structure And Union.

When you need to store elements of different data types is the correct answer to “When should you use a structure instead of an array in C”. This question is standard in competitive examination syllabi for Structure And Union.

To declare a union without a name is the correct answer to “What is the purpose of an anonymous union in C”. This question is standard in competitive examination syllabi for Structure And Union.

. (dot) is the correct answer to “Which keyword is used to access a member of a nested structure in C”. This question is standard in competitive examination syllabi for Structure And Union.

It saves memory by sharing the same memory location is the correct answer to “What is the main advantage of using a union in C”. This question is standard in competitive examination syllabi for Structure And Union.

0 bytes is the correct answer to “What is the size of an empty structure in C”. This question is standard in competitive examination syllabi for Structure And Union.

No, never is the correct answer to “In C, can you compare two structures using the equality operator (==)”. This question is standard in competitive examination syllabi for Structure And Union.

To represent multiple data types using the same memory location is the correct answer to “What is the primary use of a union in a C program”. This question is standard in competitive examination syllabi for Structure And Union.

myStruct array[] is the correct answer to “How do you declare an array of structures in C”. This question is standard in competitive examination syllabi for Structure And Union.

Function is the correct answer to “Which of the following is not a valid type for a structure member in C”. This question is standard in competitive examination syllabi for Structure And Union.

Yes, but with compiler-specific limitations is the correct answer to “In C, can you have a structure as a member of itself (a recursive structure)”. This question is standard in competitive examination syllabi for Structure And Union.

To calculate the offset of a structure member is the correct answer to “What is the purpose of the offsetof macro in C”. This question is standard in competitive examination syllabi for Structure And Union.

typedef is the correct answer to “Which keyword is used to create a new name for an existing data type in C”. This question is standard in competitive examination syllabi for Structure And Union.

Only one member of a union at any one time. is the correct answer to “How many union members can be initialized”. This question is standard in competitive examination syllabi for Structure And Union.

1 is the correct answer to “What will be the output of the following C code? #include <stdio.h> int main() { typedef struct p *q; struct p { int x; char y; q ptr; }; struct p p = {1, 2, &p}; printf("%d\n", p.ptr->x); return 0; }”. This question is standard in competitive examination syllabi for Structure And Union.

Depends on the standard is the correct answer to “Can the following C code be compiled successfully? #include <stdio.h> struct p { int k; char c; float f; }; int main() { struct p x = {.c = 97, .f = 3, .k = 1}; printf("%f\n", x.f); }”. This question is standard in competitive examination syllabi for Structure And Union.

Nothing is the correct answer to “What will be the output of the following C code? #include <stdio.h> int *(*(x()))[2]; typedef int **(*ptrfoo)())[2]; int main() { ptrfoo ptr1; ptr1 = x; ptr1(); return 0; } int *(*(x()))[2] { int (*ary)[2] = malloc(sizeof * ary); return &ary; }”. This question is standard in competitive examination syllabi for Structure And Union.

1 and 2 is the correct answer to “Which of the following share a similarity in syntax? 1. Union, 2. Structure, 3. Arrays and 4. Pointers”. This question is standard in competitive examination syllabi for Structure And Union.