合并两个数组的相同索引对象 [英] Combine same-index objects of two arrays

问题描述

说我有两个对象数组，像这样:

Say I have two arrays of objects, like so:

var arr1 = [{name: 'Jay'}, {name: 'Bob'}];
var arr2 = [{age: 22}, {age: 30}];

我想要一个这样的组合数组:

I want a combined array like so:

var arr3 = [{name: 'jay', age: 22}, {name: 'Bob', age: 30}];

您可以放心地假设两个初始数组的索引将彼此匹配，这意味着arr1的索引0将始终与arr2的索引0匹配.

You can safely assume that the two initial arrays will have indexes matching each other, meaning index 0 of arr1 will always go with index 0 of arr2.

最快的方法是什么?我在想象一个嵌套在另一个forEach循环内的forEach循环，并使用arr2的当前对象扩展arr1的每个对象，但是我觉得这可能太复杂了.

What would be the fastest way to accomplish this? I was imagining a forEach loop nested inside another forEach loop and extending each object from arr1 with the current object from arr2, but I feel this may be too complex.

推荐答案

您可以迭代一个数组，并使用第一次迭代中的索引创建一个新数组.有很多方法可以做到这一点.这是一个:

You can just iterate one array and create a new array using the index from the first iteration. There are many ways to do this. Here's one:

    var arr1 = [{name: 'Jay'}, {name: 'Bob'}];
    var arr2 = [{age: 22}, {age: 30}];

    var combined = arr1.map(function(item, index) {
        return {name: item.name, age: arr2[index].age};
    });
    document.write(JSON.stringify(combined));

如果您确实想要最大的性能，则必须在许多不同的浏览器中测试多种方案.例如，有时for循环比某些浏览器中的内置数组方法要快.

If you really want the maximum performance, you'd have to test a number of schemes in a number of different browsers. For example, sometimes a for loop is faster than the built-in array methods in some browsers.

var arr1 = [{name: 'Jay'}, {name: 'Bob'}];
var arr2 = [{age: 22}, {age: 30}];
var combined = [];

for (var i = 0; i < arr1.length; i++) {
  combined[i] = {name: arr1[i].name, age: arr2[i].age};
}

document.write(JSON.stringify(combined));

仅供参考，for循环选项(第二个选项)在所有三个浏览器中的

FYI, the for loop option (the second option) looks quite a bit faster in all three browsers here in a jsperf.

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