What is passing by reference

What is passing by reference?

Answer:

Method of passing arguments to a function which takes parameter of type reference. for example:

void swap( int & x, int & y )

{

int temp = x;

x = y;

y = temp;

} int a=2, b=3;

swap( a, b );

Basically, inside the function there won't be any copy of the arguments "x" and "y" instead they refer to original variables a and b. so no extra memory needed to pass arguments and it is more efficient.