Difference Between Structure And Union

 DIFFERENCE BETWEEN STRUCTURE AND UNION

Difference Between Structure And Union

	Structure	Union
1	Structures are used to group a number of different variables together which enables us treat a number of different variables stored in different place in memory.	Union are used to group a number of different variables together which enables us to treat the same space in memory as a number of different variables.
2	Syntax: struct structure_name { Data_type member; ........ }; struct structure_name  structure_variable;	Syntax: union structure_name { Data_type member; ........ }; union structure_name  structure_variable;
3	Example: #include<stdio.h> #include<conio.h> void main() {   struct try   {       int i;       char ch[2];   };   struct try t;   t.ch[0]=50;   t.ch[1]=30;   t.i=512;   printf("t.i=%d\n",t.i);   printf("t.ch[0]=%d\n",t.ch[0]);   printf("t.ch[1]=%d",t.ch[1]); } Output: t.i = 512 t.ch[0] = 50 t.ch[1] = 30 Reason: t.ch[0] , t.ch[1] and t.i values are stored in different memory locations there for, no values are changed	Example: #include<stdio.h> #include<conio.h> void main() { union try {       int i;       char ch[2]; }; union try t;   t.ch[0]=50;   t.ch[1]=30;   t.i=512; printf("t.i=%d\n",t.i); printf("t.ch[0]=%d\n",t.ch[0]); printf("t.ch[1]=%d",t.ch[1]); } Output: t.i = 512 t.ch[0] = 0 t.ch[1] = 2 Reason: Values of t.ch[0] and t.ch[1] i.e. 50 and 30 , is changed to 0 and 2 respectively after t.i is assigned with 512. This happens because t.ch[0] and t.ch[1] share the same memory.