If you pass an argument by reference when calling a procedure, the procedure access to the actual variable in memory. As a result, the variable’s value can be changed by the procedure. If you pass variable as reference and when you modify the value in the method, the variable in the call site will also be modified.
the sub program is given a copy of the data instead of actual variable in the memory. This means that it cannot pass any changes to it to the main program.
- CASE 1