The size of integer variable is 2 bytes.

Eg:
   if u declare like,
     
      int a;

     the compiler will allocate the size of the variable a, 
to 2 bytes bcoz it is an int variable. 

     If u want to know the size of any other 
variables,structures,etc. use the sizeof() function.

Eg:

    int a;
    sizeof(a);

  this will print 2 which is the size of the int datatype.