在 JavaScript ES6 中是否有一种函数式的方式来初始化一个数组? [英] Is there a functional way to init an array in JavaScript ES6?

问题描述

我终于放弃了，写了一个 for 循环来初始化一个简单的对象数组，其中每个对象都有一个递增的计数器 (id) 作为对象的属性.换句话说，我只想:

I finally gave up and wrote a for loop to initialize a simple array of objects where each object has an incremented counter (id) as an attribute of the object. In other words, I just want:

var sampleData = [{id: 1},{id: 2},...];

我希望有一个紧凑的语法，我可以把它放在我的 return 语句中.

I was hoping for a compact syntax I could just put on my return statement.

let sampleData = [];
for (var p = 0; p < 25; p++){
    sampleData.push({id: p});
}

return {
    data: sampleData,
    isLoading: true
};

推荐答案

Array.from() 是一个很好的方法.您可以传递一个 {length: somlength} 对象或其他一些类似数组的对象和一个定义每个项目的函数.该函数的第一个参数(调用它 _ 只是为了表明它没有被使用)将是我们传入的数组中的项(但我们只传入了一个长度，所以它没有多大意义)，第二个i是索引，用于你的id:

Array.from() is a nice way to do this. You can pass a {length: somlength} object or some other array-like object and a function that defines each item. The first argument (calling it _ just to indicate it's not used) to that function would be the item from an array we passed in (but we only passed in a length so it doesn't mean much), the second i is the index, which is used for your id:

let sampleData = Array.from({length: 10}, (_, id) => ({id}))

console.log(sampleData)

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