在Haxe for Flash中__new__的含义是什么？

Question

I saw some code (written for Flash) that looks like this:

var _array:Array<Int> = untyped __new__(Array, 10);

And I find it creates an Array and with a length of 10. However, when I try something like:

var _array:Array<Int> = untyped __new__(Array, 1, 2);

It creates an Array which has two elements. I'm confused by this, what's the real meaning of __new__ ?

Answer 1

It is Haxe "magic", see the wiki .

The __new__ is to call the native constructor, in the case of Array , it is different from what Haxe exposes ( Array in Haxe doc vs Array in AS3 doc ).

Basically using __new__ initializes the Array with a length and/or values without manually doing:

var array = [];
for(i in 0...len) array.push(0);