Question

Give one example that will show that pass by value, pass by Reference, pass by name, pass by value result are all different.

Answer 1

Examples:

pass by value:

void incrementCount(int count)//pass by value

{

  count=count+1;//increments the value of count inside the function

}

int main()

{

  int count=0;// initialze the variable count

  int result=0;//  initialze the variable result

  incrementCount(count);//call increment function

  cout<<"Pass by value\n";

  cout<<"Count:";

  cout<<count;//prints the value of count after the function call

  return 0;

}

pass by reference

void incrementCount(int & count)//& to pass by reference

{

  count=count+1;//increments the value of count

}

int main()

{

  int count=0;//initialize the variable count

  int result=0;// initialize the variable result

  incrementCount(count);//increment value of count

  cout<<"Pass by Reference\n";

  cout<<"Count:";

  cout<<count;//prints count after the function call

  return 0;

}

pass by name:

real procedure Sum(j, lo, hi, Ej);
  value lo, hi;
  integer j, lo, hi; real Ej;
begin
  real S;
  S := 0;
  for j := lo step 1 until hi do
    S := S + Ej;
  Sum := S
end;

pass by value result:

#include <iostream>
#include <string.h>
using namespace std;

void swap(int a, int b)
{

  int temp;
    temp = a;
    a = b;
    b = temp;
}

int main()
{
  int value = 2;
  int  list[5] = {1, 3, 5, 7, 9};


  swap(value, list[0]);

  cout << value << "   " << list[0] << endl;

  swap(list[0], list[1]);

  cout << list[0] << "   " << list[1] << endl;

  swap(value, list[value]);

  cout << value << "   " << list[value] << endl;

}