Union in c language

Union in c language

• 1.
  Union in C
• 2.
  Definition  Unions areconceptually similar to structures.  The syntax of union is also similar to that of structure.  The only differences is in terms of storage.  In structure each member has its own storage location, whereas all members of union uses a single shared memory location which is equal to the size of its largest data member.
• 4.
   This impliesthat although a union may contain many members of different types, it cannot handle all the members at same time. A union is declared using union keyword.  This declares a variable It1 of type union item. This union contains three members each with a different data type. However only one of them can be used at a time. This is due to the fact that only one location is allocated for a union variable, irrespective of its size. The compiler allocates the storage that is large enough to hold largest variable type in the union. In the union declared above the member x requires 4 bytes which is largest among the members in 16-bit
• 5.
  Accessing a UnionMember  Syntax for accessing union member is similar to accessing structure member,
• 6.
  Complete Example forUnion here, the values of a and b get corrupted and only variable c prints the expected result. This is because in union, the memory is shared among different data types. Hence, the only member whose value is currently stored will have the memory.