同时映射和过滤数组 [英] Map and filter an array at the same time

问题描述

我有一个对象数组，我想迭代生成一个新的过滤数组。但是，我还需要根据参数从新数组中过滤掉一些对象。我正在尝试这个：

I have an array of objects that I want to iterate over to produce a new filtered array. But also, I need to filter out some of the objects from the new array depending of a parameter. I'm trying this:

function renderOptions(options) {
    return options.map(function (option) {
        if (!option.assigned) {
            return (someNewObject);
        }
    });   
}

这是一个好方法吗？有更好的方法吗？我愿意使用任何库，例如lodash。

Is that a good approach? Is there a better method? I'm open to use any library such as lodash.

推荐答案

你应该使用 Array.reduce 为此。

var options = [
  { name: 'One', assigned: true }, 
  { name: 'Two', assigned: false }, 
  { name: 'Three', assigned: true }, 
];

var reduced = options.reduce(function(filtered, option) {
  if (option.assigned) {
     var someNewValue = { name: option.name, newProperty: 'Foo' }
     filtered.push(someNewValue);
  }
  return filtered;
}, []);

document.getElementById('output').innerHTML = JSON.stringify(reduced);

<h1>Only assigned options</h1>
<pre id="output"> </pre>

更多信息： https://developer.mozilla.org/en-US/docs/ Web / JavaScript / Reference / Global_Objects / Array / Reduce

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