Call By Reference

Addresses of the parameters are copied to the function. Whatever the modifications are done in function, those changes are reflects in calling function.

Use & (ampersand) operator is used in the actual parameter.

Advantages of the call by reference we can send more than one value from the function to calling function.

Ex: swap(&a,&b);

Example Program:

void main()

{

 void swap(int *,int*);

int a,b;

a=2;

b=3;

swap(&a,&b);

printf("a=%d\nb=%d\n",a,b);

}

void swap(int *x,int *y)

{

 int temp=x;

 x=y;

 y=temp;

}

Difference Between Call by value and Call by Reference

Call by value	Call by reference
1.       The variable/value/expression is sent to the function is known as call by value.	1.       If the address is sent to the function it is known as call by reference
2.       Syntax: function(variable,variable2);	3.       Syntax:function(&variable,&variable2);
4.here formal parameters is variable Ex: intx	4.       Here formal parameters is pointers Ex:int*x
5.       If the value is sent to the function ,that value cannot be modified	6.       Whenthe address is sent to the function the value is modified by using ‘*’operator

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