Structure and Union in C

structures in C

A structure is a user-defined data type available in C that allows to combining data items of different kinds. Structures are used to represent a record. 

Defining a structure: To define a structure, you must use the struct statement. The struct statement defines a new data type, with more than or equal to one member. The format of the struct statement is as follows:

struct [structure name]
   {
       member definition;
       member definition;
       ...
       member definition;
   };

A union is a special data type available in C that allows storing different data types in the same memory location. You can define a union with many members, but only one member can contain a value at any given time. Unions provide an efficient way of using the same memory location for multiple purposes. 

Defining a Union: To define a union, you must use the union statement in the same way as you did while defining a structure. The union statement defines a new data type with more than one member for your program. The format of the union statement is as follows: 

 

union [union name]
    {
       member definition;
       member definition;
       ...
       member definition;
    };