In call by value copy actual parameter into formal
#include<stdio.h>
void main()
{
int a=5;
int b=f(a); //passed as f(5)
printf("%d",b); //output should be 5 as we passed x=5 which got copied in b
}
int f(int x) //x==5
{
x=+5; // x=+5 here we are storing positive integer 5 in x
return x; // updating actual parameter
}