Thread: Function Help..........please

try some of the tutorials on this site

Here's a basic rundown:

Functions require the following:

1) a return type
2) a name
3) arguments
4) a function body, enclosed in { }

Thus:

void myFunc( void ) { cout << "Yo. This is a valid function." << endl; }
int myFun( int x ) { cout << "X is " << x << endl; return x; }

Etc...

Keep in mind, a function has to know of another function before it can use it. Do do this, you must either:

a) declare the function before a function calls it
b) define the function before a function calls it
c) declare the function in the body of the function that wishes to call it

Consider:

void fun1( void ) { cout << "Hi!"; }
void fun2( void ) { fun1( ); }

This works, because 'fun1' is defined before 'fun2' calls it.
If we had 'fun2' before 'fun1', then 'fun2' would not know of 'fun1'.

We could simply reference the function (declare it) first:

void fun3( void );
void fun4( void );
void fun5( void );

... then later on we actually 'define' the functions:

void fun3( void )
{
fun5( ); //valid because we've defined them above
}

void fun4( void )
{
fun3( ); //valid for the same reason
}

void fun5( void )
{
cout << "Whee...." << endl;
}

Now then, let's say we haven't declared or defined 'fun6' yet, but we wanted to have 'fun8' use it. We could do:

Code:

void fun8( void )
{
    void fun7( void ); //declare it locally so fun8 can call it

    fun7( ); //now we can use it assuming it exists some place
}

Quzah.