4.3 Method

While variables hold data, methods are defining behavior of a program by hosting expressions. We have seen method fields in every code example of this document with even the initial Hello World example containing a main method:

    Multi-line comments for documentation.
class Main {
    static public function main():Void {
        // Single line comment
        trace("Hello World");

Methods are identified by the function keyword. We can also learn that they

  1. have a name (here: main),
  2. have an argument list (here: empty ()),
  3. have a return type (here: Void),
  4. may have access modifiers (here: static and public) and
  5. may have an expression (here: {trace("Hello World");}).

We can also look at the next example to learn more about arguments and return types:

class Main {
  static public function main() {
    myFunc("foo", 1);

  static function myFunc(f:String, i) {
    return true;

Arguments are given by an opening parenthesis ( after the field name, a comma , separated list of argument specifications and a closing parenthesis ). Additional information on the argument specification is described in Function Type.

The example demonstrates how type inference can be used for both argument and return types. The method myFunc has two arguments but only explicitly gives the type of the first one, f, as String. The second one, i, is not type-hinted and it is left to the compiler to infer its type from calls made to it. Likewise, the return type of the method is inferred from the return true expression as Bool.