Array.prototype.fill() 与对象传递引用而不是新实例 [英] Array.prototype.fill() with object passes reference and not new instance

问题描述

我有点玩弄并试图实例化一个长度为 x 的新数组，其中该数组的所有元素都被初始化为一个值 y:

I was toying a bit and was trying to instantiate a new array of length x, where all elements of that array were initialized to a value y:

var arr = new Array(x).fill(y);

如果y 的值不是一个对象，这很有效.这意味着如果 y 是一个对象，则以下为真:

This works well if the value of y is anything other than an object. Meaning that if y is an object, the following is true:

var arr = new Array(2).fill({});
arr[0] === arr[1]; //is true;
arr[0].test = 'string';
arr[1].test === 'string'; //is also true;

有什么方法可以说明在使用填充函数时应该为每个元素创建一个新对象吗?还是我应该将其转换为循环?

Is there any way to state that a new object should be created for each element while using the fill-function? Or should I just convert it to a loop?

推荐答案

你可以先用任意值(例如 undefined)fill 数组，然后你就会能够使用map:

You can first fill the array with any value (e.g. undefined), and then you will be able to use map:

var arr = new Array(2).fill().map(u => ({}));

var arr = new Array(2).fill().map(Object);

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