Explain union, C/C++ Programming

Assignment Help:

Unions

A union is also like a structure, except that only single variable in the union is stored in the allocated memory at a time. It is a collection of mutually exclusive variables, which means all of its member variables share the similar physical storage and only one variable is explained at a time. The size of the union is equal to the largest member variables. A union is defined as follows :

                union tag

                 {

                                type memvar1;

                                type memvar2;

                                type memvar3;

                                :

                                :

                 };

 

A union variable of this data type can be declared as follows,

Union tag variable_name;

e.g.

                union utag

                 {

                                int num;

                                char ch;

                 };

                union tag filed;

The above union will have two bytes of storage allocated to it. The variable num can be accessed as field.sum and ch is accessed as field.ch. At any time, only one of these two variables,  can be referred to. Any change made to single variable affects another.

 


Related Discussions:- Explain union

Boardcoloring., Smugglers are becoming very smart day by day. Now they have...

Smugglers are becoming very smart day by day. Now they have developed a new technique of sending their messages from one smuggler to another. In their new technology, they are send

Described the order that objects in an array is destructed?, Described the ...

Described the order that objects in an array is destructed?

Define the bitwise operators in c language, Define the Bitwise Operators in...

Define the Bitwise Operators in c language? C has distinction of supporting special operators that known as bit wise operators for manipulation of data at bit level. These oper

Area under curve, Write a program to find the area under the curve y = f(x)...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b.

Function returning object, F u nction Returning Object: This program ...

F u nction Returning Object: This program is like to the previous program except the function returns object.  The main rule to be remembered is the function returning obj

Explain concept of object initialization, Object Initialization An obje...

Object Initialization An object of a derived class can be initialized to an object of a base class. If both the classes have similar data members, then no specific constructor

Make c code works equally on 64 and 32 bit, Project Description: I have ...

Project Description: I have a code that works different on 64 bit and 32 bit system. Code is relative to some crypt functions, similar, but not equal to: I have to move fr

Open and close ?les for writing, If you have computed a number (stored as a...

If you have computed a number (stored as a ?oating-point value) and want to display this on a plot (i.e. as a character string) you have to convert it into a STRING. That is we wan

Loop statement, write a c++ program to accept 3 numbers and find the larges...

write a c++ program to accept 3 numbers and find the largest of 3 numbers

Define constructors-extract and insert operators, For your class to work pr...

For your class to work properly, you'll need to define appropriate constructors, extract and insert operators, and of course arithmetic operators. (If you wanted to use it as a gen

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd