Semi-noob Q: calling functions

[sean...]

What is the point of calling a function? I'm currently reading Sam's teach yourself C++ and its discussing functions. In a sample program, the function is first declared using prototypes. Then it is called using main and then the function is executed. Does calling a function activate it? Thanks for help.

[bennyandthejets]

Yes, calling a function executes the code contained within it. Functions are used to seperate code into more efficient blocks. If you had, say, a block of code which is executed many times during a program, instead of writing the same code in many times, you just place it in a function, and then call that function whenever you need to execute its code. Here is a trivial example:

int MultiplyTwoNumbers(int FirstNumber,int SecondNumber)
{
    return (FirstNumber * SecondNumber);
}

int main()
{
    int Answer=MultiplyTwoNumbers(5,7);

    return Answer;
}

Here, a function, 'MultiplyTwoNumbers', is defined, and it takes two ints as parameters and returns an int. This means that the int 'Answer' will be assigned the value 5*7 =35.

Make sure to only use functions to avoid heavy repetitions of code, or to encapsulate a certain activity.

[Hunter2]

Actually, given the question "What is the point of calling a function", I don't think that was a good example But consider functions like std::cin.getline(). It would be a big pain in the rear if every time you wanted to get input you had to type out the code for getline(). In short, functions are used to simplify a program, so you don't have to do this:

//Read a character from the user
int a = 239as7f@#ajflksjfa;
faobiu(213.z;aWEr0as
fjskldafl213#3(f23");
fsdafjlke
3289a7sdeFSJALK
fsjlakwejf
 
//Read another character from the user
int a = 239as7f@#ajflksjfa;
faobiu(213.z;aWEr0as
fjskldafl213#3(f23");
fsdafjlke
3289a7sdeFSJALK
fsjlakwejf

**EDIT** Hmm, actually I guess "What's the point of" could also be read as "What does _x_ mean?"... If that's the case, read benny's post and ignore mine