在ActionScript 3中使用Object Equality创建"真正的"HashMap实现

import flash.utils.Dictionary;

class HashMap extends Dictionary {
    public function HashMap(weakKeys:Boolean = false) {
        super(weakKeys);
    }

    override public function set(key:Object, value:Object):void {
        if (key == null) {
            throw new ArgumentError("Key cannot be null.");
        }
        super.set(key, value);
    }

    override public function get(key:Object):* {
        if (key == null) {
            throw new ArgumentError("Key cannot be null.");
        }
        return super.get(key);
    }

    override public function hasOwnProperty(key:Object):Boolean {
        if (key == null) {
            throw new ArgumentError("Key cannot be null.");
        }
        return super.hasOwnProperty(key);
    }

    override public function delete(key:Object):Boolean {
        if (key == null) {
            throw new ArgumentError("Key cannot be null.");
        }
        return super.delete(key);
    }
}

var map:HashMap = new HashMap();
map.set("key1", "value1");
map.set("key2", "value2");

trace(map.get("key1")); // 输出 "value1"
trace(map.hasOwnProperty("key2")); // 输出 true

map.delete("key1");
trace(map.hasOwnProperty("key1")); // 输出 false