按“组"对二维数组求和 [英] Summing a 2D array by "group"

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本文介绍了按“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

我有一个数组形式

<预><代码>[['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减少到唯一的左侧条目.这是我想减少到

的一个例子<预><代码>[['16-24', 287588],['25-34', 287588],...]

显然这里的数字是一个人为的例子.我已经研究了 javascript 的数组减少,但我不确定如何使用它来实现这种效果

解决方案

使用 reduce() 求和和 map() 将其更改为您想要的格式.

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]] = 总数 + cur[1];返回对象;}, {} );var result = Object.keys(temp).map( function (key) { return [key, temp[key]]; });控制台日志(结果);

I have an array in the form

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

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],
...
]

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

解决方案

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);                                                             

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