如何获取数组的所有索引到新数组 [英] How to get all index of an array to new array

问题描述

我有一个要映射的数组数组.但是我的映射存在问题，因为映射所有索引不仅是我要映射的索引.我认为我可以通过仅创建要映射的数据的新数组来解决此问题.

I have an array of arrays that I am trying to map. But I am having an issue with my mapping because mapping all indexes not just the one I want it to be mapping. I figured I can work my way around this by creating a new array of only of the data I am trying to map.

如何将所有 index 2 推送到新数组中?我无法找到我要尝试做的事的例子.

How can I push all index 2 into a new array? I have not been able to find an example of what I am attempting to do.

我期望新数组的结果等于 [231、431、481]

I am expecting an outcome of a new array that equals [231, 431, 481]

这是我的代码示例:

const array = [ ["name", 1, 231], [ "name", 2, 431], ["name", 3, 481] ] 

console.log(array)

let percentage = array.map(function (num, i) {
      return 100 * ((num - array[i - 1]) / (array[i - 1]));
    });

推荐答案

您可以这样做

const array = [ ["name", 1, 231], [ "name", 2, 431], ["name", 3, 481] ] 
const arrayNew = array.map(x => x[2])
// arrayNew === [231, 431, 481]

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