Structures And Unions In C Plus Plus MCQs with Explanations

In C++, the size of a structure is determined by the sum of the sizes of its individual members, taking into account padding for alignment. The Employee structure consists of three members: an integer id , an array of characters name of size 20, and a float salary . The size of an integer is typically 4 bytes, the size of a float is also typically 4 bytes, and the size of each character in the array depends on the character set being used (usually 1 byte per character). However, due to memory alignment requirements, additional padding may be added after the name array to ensure proper alignment of subsequent members. So, the calculation of the structure size would be: int id : 4 bytes char name[20] : 20 bytes Padding to align salary to the next 4-byte boundary (assuming 4-byte alignment) float salary : 4 bytes Total: 4 bytes (id) + 20 bytes (name) + 4 bytes (padding) + 4 bytes (salary) = 32 bytes. Therefore, the correct answer is Option D: 32 bytes.

A user-defined data type containing variables of different data types is the correct answer to “What is a structure in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

struct is the correct answer to “Which keyword is used to define a structure in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Using the dot operator is the correct answer to “What is the correct way to access members of a structure in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

To create an alias for data types is the correct answer to “What is the purpose of typedef in C++ structures”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

structName variableName is the correct answer to “How do you declare a structure variable in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

101 is the correct answer to “What is the output of the following code: struct Student { int roll; }; Student s1; s1.roll = 101; cout << s1.roll; in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

To group related data together is the correct answer to “What is the purpose of using structures in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

All of the above is the correct answer to “What is the correct way to pass a structure to a function in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

A user-defined data type that allows storing different data types in the same memory location is the correct answer to “What is a union in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

In a structure, each member has its own memory space, while in a union, all members share the same memory space is the correct answer to “What is the difference between a structure and a union in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

structName *ptr is the correct answer to “What is the correct syntax to define a structure pointer in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

0.416666667 is the correct answer to “What is the output of the following code: union Data { int x; char y; }; Data d; d.x = 10; d.y = 'A'; cout << d.x << " " << d.y; in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

To save memory space is the correct answer to “What is the purpose of using unions in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Size of the structure is the correct answer to “What does the 'sizeof' operator return when used with a structure in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

struct structName { /* members */ } is the correct answer to “What is the correct syntax to declare a structure with a tag name in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Using the arrow operator (->) is the correct answer to “What is the correct way to access structure members through a pointer in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

By default, members of a class are private, while members of a structure are public is the correct answer to “What is the difference between a structure and a class in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

10 20 is the correct answer to “What is the output of the following code: struct Point { int x, y; }; Point p1; p1.x = 10; p1.y = 20; cout << p1.x << " " << p1.y; in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

To create an alias for a data type is the correct answer to “What is the purpose of the 'typedef' keyword in C++ structures”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

union is the correct answer to “Which keyword is used to declare a union in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

union unionName { /* members */ } is the correct answer to “What is the correct syntax to define a union in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Depends on the compiler is the correct answer to “What is the output of the following code: struct Book { char title[50]; int pages; }; Book b; cout << sizeof(b); in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Garbage value is the correct answer to “What is the output of the following code: union Number { int x; float y; }; Number n; n.x = 10; cout << n.y; in C++”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

structure specifier is the correct answer to “The declaration of the structure is also called as”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

252 is the correct answer to “What will be the output of the following C++ code? #include <iostream> using namespace std; struct sec { int a; char b; }; int main() { struct sec s ={25,50}; struct sec *ps =(struct sec *)&s; cout << ps->a << ps->b; return 0; }”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

19845 is the correct answer to “What will be the output of the following C++ code? #include <iostream> using namespace std; struct Time { int hours; int minutes; int seconds; }; int toSeconds(Time now); int main() { Time t; t.hours = 5; t.minutes = 30; t.seconds = 45; cout << "Total seconds: " << toSeconds(t) << endl; return 0; } int toSeconds(Time now) { return 3600 * now.hours + 60 * now.minutes + now.seconds; }”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

123 john is the correct answer to “What will be the output of the following C++ code? #include <iostream> #include <string.h> using namespace std; int main() { struct student { int num; char name[25]; }; student stu; stu.num = 123; strcpy(stu.name, "John"); cout << stu.num << endl; cout << stu.name << endl; return 0; }”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

is the correct answer to “What will be used when terminating a structure”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

members is the correct answer to “The data elements in the structure are also known as what”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

struct a_struct {int a;} is the correct answer to “Which of the following is a properly defined structure”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

it will not allocate any memory is the correct answer to “What will happen when the structure is declared”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

Adidas $ 9.99Adidas $ 1.11 is the correct answer to “What will be the output of the following C++ code? #include <iostream> using namespace std; int main() { struct ShoeType { string style; double price; }; ShoeType shoe1, shoe2; shoe1.style = "Adidas"; shoe1.price = 9.99; cout << shoe1.style << " $ "<< shoe1.price; shoe2 = shoe1; shoe2.price = shoe2.price / 9; cout << shoe2.style << " $ "<< shoe2.price; return 0; }”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.

b->var is the correct answer to “Which of the following accesses a variable in structure *b”. This question is standard in competitive examination syllabi for Structures And Unions In C Plus Plus.