The most difficult aspect is deciding how to break up programming logic into functions. The mechanics of developing a function in PHP, on the other hand, are quite easy. Just use the function
keyword, give it a name, and follow it with parentheses.
The code itself goes inside curly braces as follows:
function someName ($parameter) { $result = 'INIT'; // one or more statements which do something // to affect $result $result .= ' and also ' . $parameter; return $result; }
You can define one or more parameters. To make one of them optional, simply assign a default value. If you are not sure what default value to assign, use
NULL
:function someOtherName ($requiredParam, $optionalParam = NULL) { $result = 0; $result += $requiredParam; $result += $optionalParam ?? 0; return $result; }