Chapter 11.11, Problem 11.17CP

Program Plan Intro

Union:

In C++, the union is a user-define data type, which contains different type of elements with different lengths.

• It uses single memory location to hold more than one variable. It takes the memory of the largest data type.
• It conserves memory as it stores all the members in the same memory location.
• Union variable can initialize in main function within the program. Then initialize the union members using the union variable.
• Union variable can be declared in the type of array and the entire array elements can be accessed through a loop.

 Declaration of union:

The declaration of union is the same as a structure with the only difference that, instead of using a keyword “struct”, the keyword “union” should be used.

Example:

union Score

{

int rollNo;

float marks;

};

The “Score” is the union variable which is defined with the two members:  “rollNo( a int)” and “marks (a float)”. The union variable will take up as much memory as the largest member.