通过“组"对二维数组求和-前端问题

Summing a 2D array by quot;groupquot;(通过“组对二维数组求和)

本文介绍了通过“组"对二维数组求和的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我在表单中有一个数组

[
['16-24', 192081],
['16-24', 94452],
['16-24', 1055],
['25-34', 192081],
['25-34', 94452],
['25-34', 1055],
...
]

我想将数组中的许多项目缩减为唯一的左侧条目.这是我想减少到的一个例子

I have many items in the array that I'd like to reduce down to the unique left-hand entries. This is an example of what I'd like to reduce down to

[
['16-24', 287588],
['25-34', 287588],
...
]

显然这里的数字是一个人为的例子.我查看了 javascript 的数组 reduce，但我不确定如何使用它来实现此效果

Obviously the numbers here are a contrived example. I've looked into javascript's array reduce but I'm unsure how to use it to achieve this effect

推荐答案

使用reduce()求和，map()改成你想要的格式.

Use reduce() to sum and map() to change it to the format you want.

var vals = [
['16-24', 192081],
['16-24', 94452],
['16-24', 1055],
['25-34', 192081],
['25-34', 94452],
['25-34', 1055]
];

var temp = vals.reduce(function (obj, cur) {
    var total = obj[cur[0]] || 0;
    obj[cur[0]] = total + cur[1];
    return obj;
}, {} );

var result = Object.keys(temp).map( function (key) { return [key, temp[key]]; });
console.log(result);

这篇关于通过“组"对二维数组求和的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！