3 replies to this topic

[Termana]

First off, I will explain the difference between pass by value and pass by reference.

When you pass by value to a function (for example), it will copy the value stored in the variable you pass and if you change the copied variable it will not change the variable in the function that called the function.

However, when you pass by reference, you pass the address of variable, rather then the variable itself. So when you change the variable in the function, it WILL be changed in the function that called this function.

Since whenever you have probably used a function with parameters, I wont show how to pass by value, as that is what happens when you call a function with parameters. But I will show you the code to pass by reference and then explain it.

void TestFunction(int &variable1)

{

variable1 = 1337;

}

All I have done it put a & in front of the passed variable declaration. So if we had something like this:

#include <cstdlib>

#include <iostream>


using namespace std;


void TestFunction(int &variable1)

{

    variable1 = 1337;

}


int main(int argc, char *argv[])

{

    int a;

    a = 7;

    TestFunction(a);

    cout << a << endl;

    system("PAUSE");

    return EXIT_SUCCESS;

}

It will print the number 1337, because we called TestFunction, however if we A) Didn't call TestFunction or B) Did not put the & in front of variable1 - it would just print 7.

[amrosama]

nice and simple tutorial termana
+rep

[MeTh0Dz]

This sentence basically fucks your entire tutorial.

Quote

However, when you pass by reference, you pass the address of variable, rather then the variable itself.

When you are talking about stuff like this, you need to make sure that you are extremely precise and explicit in what you say.

[WingedPanther]

I have to agree with Methodz. Passing a pointer and passing a reference allow you to do the same thing, but the details are quite different. A reference (which you used in your examples) is not a pointer, but more of an alias.