如何获取javascript对象属性的子集

本文翻译自：How to get a subset of a javascript object's properties

Say I have an object: 说我有一个对象：

elmo = { 
  color: 'red',
  annoying: true,
  height: 'unknown',
  meta: { one: '1', two: '2'}
};

I want to make a new object with a subset of its properties. 我想用其属性的子集创建一个新对象。

 // pseudo code
 subset = elmo.slice('color', 'height')

 //=> { color: 'red', height: 'unknown' }

How may I achieve this? 我该如何实现？

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#1楼

参考：https://stackoom.com/question/1Cblw/如何获取javascript对象属性的子集

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#2楼

There is nothing like that built-in to the core library, but you can use object destructuring to do it... 核心库中没有内置的东西，但是您可以使用对象分解来实现。

const {color, height} = sourceObject;
const newObject = {color, height};

You could also write a utility function do it... 您也可以编写一个实用程序函数来做...

const cloneAndPluck = function(sourceObject, keys) {
    const newObject = {};
    keys.forEach((obj, key) => { newObject[key] = sourceObject[key]; });
    return newObject;
};

const subset = cloneAndPluck(elmo, ["color", "height"]);

Libraries such as Lodash also have _.pick() . Lodash等库也具有_.pick() 。

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#3楼

How about: 怎么样：

function sliceObj(obj) {
  var o = {}
    , keys = [].slice.call(arguments, 1);
  for (var i=0; i

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#4楼

I suggest taking a look at Lodash ; 我建议看一看Lodash ； it has a lot of great utility functions. 它具有许多强大的实用程序功能。

For example pick() would be exactly what you seek: 例如pick()正是您要寻找的：

var subset = _.pick(elmo, ['color', 'height']);

fiddle 小提琴

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#5楼

function splice()
{
    var ret = new Object();

    for(i = 1; i < arguments.length; i++)
        ret[arguments[i]] = arguments[0][arguments[i]];

    return ret;
}

var answer = splice(elmo, "color", "height");

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#6楼

Note: though the original question asked was for javascript, it can be done jQuery by below solution 注意：尽管最初提出的问题是针对javascript的，但可以通过以下解决方案完成jQuery

you can extend jquery if you want here is the sample code for one slice: 您可以扩展jquery，如果您想获得一个切片的示例代码：

jQuery.extend({
  sliceMe: function(obj, str) {
      var returnJsonObj = null;
    $.each( obj, function(name, value){
        alert("name: "+name+", value: "+value);
        if(name==str){
            returnJsonObj = JSON.stringify("{"+name+":"+value+"}");
        }

    });
      return returnJsonObj;
  }
});

var elmo = { 
  color: 'red',
  annoying: true,
  height: 'unknown',
  meta: { one: '1', two: '2'}
};


var temp = $.sliceMe(elmo,"color");
alert(JSON.stringify(temp));

here is the fiddle for same: http://jsfiddle.net/w633z/ 这是相同的小提琴： http : //jsfiddle.net/w633z/