Unions

A union is a variable that may hold objects of different types and sizes. They provide a way to hold different kinds of data in a single area of storage

Example

      /* this union can hold any one, and only one, of the types below */
      union u_tag {
        int ival;
        float fval;
        char *sval;
      } u;

Physically the union is the size of the largest of it's internal types

Objects are retrieved from the union in a manner similar to structs but the user must remember which type is currently stored in use in the union