有没有办法冻结ES6地图? [英] Is there a way to freeze an ES6 Map?

问题描述

我正在寻找冻结本机ES6地图的方法.

I'm looking for a way to freeze native ES6 Maps.

Object.freeze 和 Object.seal 似乎没有工作:

Object.freeze and Object.seal don't seem to work:

let myMap = new Map([["key1", "value1"]]);
// Map { 'key1' => 'value1' }

Object.freeze(myMap);
Object.seal(myMap);

myMap.set("key2", "value2");
// Map { 'key1' => 'value1', 'key2' => 'value2' }

这是预期的行为，因为objects和maps的冻结冻结属性不是objects，或者这可能是错误/尚未实现?

Is this intended behavior since freeze freezes properties of objects and maps are no objects or might this be a bug / not implemented yet?

是的，我知道，我可能应该使用 Immutable.js ，但是有没有ES6 Maps做到这一点的方法?

And yes I know, I should probably use Immutable.js, but is there any way to do this with native ES6 Maps?

推荐答案

@loganfsmyth ，您的回答给了我一个主意，那呢:

@loganfsmyth, your answer gave me an idea, what about this:

function freezeMap(myMap){

  if(myMap instanceof Map) {

    myMap.set = function(key){
      throw('Can\'t add property ' + key + ', map is not extensible');
    };

    myMap.delete = function(key){
      throw('Can\'t delete property ' + key + ', map is frozen');
    };

    myMap.clear = function(){
      throw('Can\'t clear map, map is frozen');
    };
  }

  Object.freeze(myMap);
}

这对我来说非常合适:)

This works perfectly for me :)

在注释中更新了 @Bergi 中的点:

Updated with points from @Bergi in the comments:

var mapSet = function(key){
  throw('Can\'t add property ' + key + ', map is not extensible');
};

var mapDelete = function(key){
  throw('Can\'t delete property ' + key + ', map is frozen');
};

var mapClear = function(){
  throw('Can\'t clear map, map is frozen');
};

function freezeMap(myMap){

  myMap.set = mapSet;
  myMap.delete = mapDelete;
  myMap.clear = mapClear;

  Object.freeze(myMap);
}

这篇关于有没有办法冻结ES6地图?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！