Category 

Type specifiers 

Syntax  

union [<union type name>] {
<type> <variable names> ;
  ...
} [<union variables>] ;

Description 

Use unions to define variables that share storage space. 

The compiler allocates enough storage in a_number to accommodate the largest element in the union. 

Unlike a struct, the members of a union occupy the same location in memory. Writing into one overwrites all others. 

Use the record selector (.) to access elements of a union .