user defined functions

[Ernie1]

Can anybody explain how user defined functions works?

example:

function foo ($arg_1, $arg_2, ..., $arg_n //what are these values and how they are defined?)
{
    echo "Example function.\n";
    return $retval; //what is returned here?
} 

[php_daemon]

User defined functions work just like the all other php functions.

$arg_1, $arg_2, ..., $arg_n are function arguments, the values that you pass to the function to work with. Ex.:

function sum($a, $b){
  return $a+$b;
}

echo sum(2,3); //outputs 5 

In the example, you see that the function is defined with two arguments which it use to add and return the result. This explains "return" as well.

Hope this helps.