Chapter 11, Problem 56RQE

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.

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;

};

 Anonymous Union:

Anonymous union are also known as unnamed union as it does not have any name.

• When declaring the anonymous union, the member variables are created in the memory.
• So, the union variables need not to be defined separately.
• It is simple to use as the members can be accessed without the dot operator.

Declaration of Anonymous Union:

union

{

member declaration;

member declaration;

};