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

Pointer declaration for class, P o i n t e r d e c l ...

P o i n t e r d e c l a r a t i o n f o r C l a s s : M m; M * p m; / / C la ss M i s d e c l a r e d a s

Explain the process of using the constructor, Using the Constructor The...

Using the Constructor There are basically three ways of creating and initializing the object. The first way to call the constructor is explicitly as :

Symbolic constant, S y m b o li c c o n s t a n t : c ...

S y m b o li c c o n s t a n t : c on s t m a x = 1 0 0 ; T h e d e f a u l t d a t a t y p e w i l l b e i n t e

Explanation of break statement, Problem 1. Explain Break and continue s...

Problem 1. Explain Break and continue statements in C++. Explanation of Break statement Explanation of Continue statement 2. Explain concepts of constructors and

Explain static variables, Static Variables Static variables have the si...

Static Variables Static variables have the similar scope s automatic variables, but, unlike automatic variables, static variables retain their values over number of function ca

How can i present printing for my class fred?, A: Use operator overloading ...

A: Use operator overloading to present a friend left-shift operator, operator #include class Fred { public: friend std::ostream& operator ... private: int i_; // onl

Reverse a string - c ++ program, Reverse a string - C ++ program: Writ...

Reverse a string - C ++ program: Write a program in c to reverse a string. int main() {     Stack theStack;     String reverse("reverse");       cout

Looping, Write a programme to display the patern.. A A B A C B A B C...

Write a programme to display the patern.. A A B A C B A B C A B A A

Abstract class Employee , I have to add virtual void calculatePay and virtu...

I have to add virtual void calculatePay and virtual void displayEmployee. How to I implement that in Salaried and Hourly Employee?

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