Comparing Haxe and ActionScript

2024-12-21

Since the Haxe programming language originated from an ActionScript 2.0 compiler, there are many similarities between the languages. In fact, a number of the minor differences between ActionScript 3.0 and Haxe can be explained if you understand this heritage.

However, as you look deeper, you will find that Haxe is a modern, strictly-typed language that takes inspiration from many of the best parts of ActionScript while adding many new and valuable features.

Basic Types

ActionScript 3

Boolean
int
Number
Object
void
Array
Vector.<String>

Haxe

Bool
Int
Float
Dynamic
Void
Array<Dynamic>
Array<String>

Package Declarations

ActionScript 3

1
2
3

package com.example.myapplication {
 
}

Haxe

1	package com.example.myapplication;

Defining a Class

ActionScript 3

public class MyClass {
 
   public function MyClass () {
 
 
   }
 
}

Haxe

class MyClass {
 
   public function new () {
 
 
   }
 
}

Loops

ActionScript 3

for (var i:uint = 0; i < 100; i++) {
 
}
 
for each (var value:String in items) {
 
}
 
for (var propertyName:String in object) {
 
}

Haxe

for (i in 0...100) {
 
}
 
for (value in items) {
 
}
 
var fields = Reflect.fields (object);
for (propertyName in fields) {
 
}

Switch Statements

ActionScript 3

switch (value) {
 
   case 1:
      trace ("Equal to 1");
      break;
 
   default:
      trace ("Not equal to 1");
      break;
 
}

Haxe

switch (value) {
 
   case 1:
      trace ("Equal to 1");
 
   default:
      trace ("Not equal to 1");
 
}

Type Inference

ActionScript 3

var hi = "Hello World";
 
// type is Object
// fails to compile in strict mode

Haxe

var hi = "Hello World";
 
// type is String
// even works for code completion

Type Casting

ActionScript 3

var car:Car = vehicle as Car;
 
var toString:String = String (10);
var toNumber:Number = Number ("10");
var toInteger:int = int (10.1);

Haxe

var car:Car = cast vehicle;
 
// or for a safe cast:
 
var car = cast (vehicle, Car);
 
var toString = Std.string (10);
var toNumber = Std.parseFloat ("10");
var toInteger = Std.int (10.1);

Type Details

ActionScript 3

if (vehicle is Car) {
 
}
 
import flash.utils.getDefinitionByName;
import flash.utils.getQualifiedClassName;
 
name = getQualifiedClassName (vehicle);
type = Class (getDefinitionByName (name);

Haxe

if (Std.is (vehicle, Car)) {
 
}
 
type = Type.getClass (vehicle);
name = Type.getClassName (type);

Checking for Null

ActionScript 3

if (object == null) {
 
}
 
if (!object) {
 
}

Haxe

1
2
3

if (object == null) {
 
}

Hash Tables

ActionScript 3

var table:Object = new Object ();
table["key"] = 100;
 
trace (table.hasOwnProperty ("key"));
 
for (var key:Object in table) {
 
   trace (key + " = " + table[key]);
 
}
 
delete table["key"];

Haxe

var table = new Map<String,Int> ();
table.set ("key", 100);
 
trace (table.exists ("key"));
 
for (key in table.keys ()) {
 
   trace (key + " = " + table.get (key));
 
}
 
table.remove ("key");

Rest Parameters

ActionScript 3

function test (...params):void {
 
}
 
test (1, 2, 3);

Haxe

function test (params:Array<Dynamic>) {
 
}
 
Reflect.makeVarArgs (test) (1, 2, 3);

Reflection

ActionScript 3

1
2
3

var foo = object["foo"];
 
bar.apply (this, [ "hi" ]);

Haxe

1
2
3

var foo = Reflect.field (object, "foo");
 
Reflect.callMethod (this, bar, [ "hi" ]);

Constants

ActionScript 3

1	private const gravity:Number = 9.8;

Haxe

1	private inline static var gravity = 9.8;

Function Types

ActionScript 3

function hello (msg:String):void {
 
}
 
var type:Function = hello;

Haxe

function hello (msg:String):Void {
 
}
 
var type:String->Void = hello;
 
// can also use Dynamic

Getters and Setters

ActionScript 3

function get x ():Number {
 
   return _x;
 
}
 
function set x (value:Number):void {
 
   _x = value;
 
}

Haxe

public var x (get, set):Float;
 
function get_x ():Float {
 
   return _x;
 
}
 
function set_x (value:Float):Float {
 
   return _x = value;
 
}

Read-Only Properties

ActionScript 3

function get x ():Float {
 
   return _x;
 
}

Haxe

public var x (default, null):Float;
 
// null allows private access
// `never` would restrict all access

Missing Features

Haxe does not currently support custom namespaces, and methods do not provide an arguments property.

Additional Features

In addition to most of the features of Actionscript 3, Haxe includes support for enums, type parameters (generics), structures, typedefs, custom iterators, conditional compilation, inlining and more.