Pass By Value

#include <iostream>
#include <stdlib.h>

using namespace std;

//We have to make a copy of number because number is can only be in the local scope and myNumber in main scope.
void test(int number) //number = 1 //It's taking the value of myNumber and setting it to the variable number.
{
    cout << number << endl;
    number++;
    cout << number << endl;
}

int main()
{

    int myNumber = 1;
    test(myNumber); //myNumber = number // number is now a copy of myNumber
    cout << myNumber << endl;

}

//You're essentially creating a copy for number in the test() scope. Then using the copy in main().