Frequently Asked C Language Interview Question & Answers

What is difference between structure and union?

Structure:

  • Struct keyword is used to define a structure.

  • Members do not share memory in a structure.

  • Any member can be retrieved at any time in a structure.

  • Several members of a structure can be initialized at once.

  • Size of the structure is equal to the sum of the size of each member.

  • Altering the value of one member will not affect the value of another.

  • Stores different values for all the members.

Union:

  • Union keyword is used to define a union.

  • Members share the memory space in a union.

  • Only one member can be accessed at a time in a union.

  • Only the first member can be initialized.

  • Size of the union is equal to the size of the largest member.

  • Change in value of one member will affect other member values.

  • Stores same value for all the members.