查找子数组的总和

本文介绍了查找子数组的总和的处理方法，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

我正在处理一个非常大的子数组数组，这些子数组的数字我想将每个子数组减少为一个总和.

I'm working on a very large array of subarrays full of numbers that I want to reduce into one sum for each subarray.

示例:

var arr = [[1,2,3], [4,5,6]]; arr.forEach(function(item) { item.reduce(function(a, b) { return a + b; }); }); console.log(arr); //I want arr to equal [[6], [15]];

我的解决方案只是返回原始数组元素

My solution just returns the original array element

推荐答案

尝试如下操作:

var arr = [[1,2,3], [4,5,6]]; var newArr = []; arr.forEach(function(item) { item = item.reduce(function(a, b) { return a + b; }); newArr.push([item]); }); console.log(newArr);

为简洁起见，您可以使用传递给forEach回调的值:当前正在迭代的项目，该项目的索引以及数组本身:

To be a bit more concise, you can use the values passed to the forEach callback: the item you're currently iterating through, the index of that item, and the array itself:

arr.forEach(function(item, index, array) { array[index] = [array[index].reduce(function (a, b) { return a + b; })]; });