How to Declare a Pointer to a Union in C?

Union is a user-defined data type in C language that can contain elements of the different data types and pointers are used to store memory addresses. In this article, we will learn how to declare a pointer to a union in C++.

Pointer to Union in C

To declare a pointer to a union first, define a union and then declare a pointer that points to the union type using the below syntax:

Syntax to Declare Pointer to Union in C

//Define Union
union unionName {
 int var1;
 float var2;
};
//declare pointer to union
union unionName *ptr;

We can also assign the pointer the address of some union variable by using the addressof(&) operator.

C Program to Declare Pointer to Union

The following programs show how to declare pointers to unions in C programming and access members using the arrow operator (->).

The intValue is: 100
The floatValue is: 3.140000