Question

Assuming the language supports these evaluation strategies, what would be the result for call by reference, call by name, and call by value?

void swap(int a; int b)
{
   int temp;
   temp = a;
   a = b;
   b = temp;
}

int i = 3;
int A[5];
A[3] = 4;
swap (i, A[3]);

Answer 1

call by value
-The changes done inside swap method are not visible after calling the method.
ie. after swap (i, A[3]);

i, A[3] values don’t get changed.

call by ref:
The changes done inside swap method are visible after calling the method.
ie. after swap (i, A[3]);

i, A[3] values get exchanged.

if you are using C++ as language then the signature of the method should be changed to reflect the pass by reference:

void swap(int& a, int& b)
{
   int temp;
   temp = a;
   a = b;
   b = temp;
}