在JavaScript中合并具有相同键的对象 [英] Merge objects with same key in javascript

问题描述

如果我有这样的对象数组，我已经很长时间试图解决这个问题了:

I have been trying to figure this out for a long time, if i have an array of objects like so:

var my_array = [
    Object {Project: A, Hours: 2},
    Object {Project: B, Hours: 3},
    Object {Project: C, Hours: 5},
    Object {Project: A, Hours: 6},
    Object {Project: C, Hours: 9}
]

我想将所有具有相同键的对象合并到一个对象中，以使它们的时间加在一起:

I want to merge all the objects with the same key together into one object, such that their hours get added up:

预期输出:

my_array = [
    Object {Project: A, Hours: 8}
    Object {Project: B, Hours: 3}
    Object {Project: C, Hours: 14}
]

如何解决此问题?以这种方式格式化数据花了我很长时间，这是最后一步！

How can I approach this issue? It has taken me a long time to get my data formatted in this way, this is the last step!

我的尝试是，我在遍历数组，不确定如何处理对象的合并:

My attempt, I get that I am looping through array, not sure how to deal with the merging of the objects:

for (var i =0; i<my_array.length; i++) {
   my_array[i].Project   // access the object project key
   my_array[i].Hours     // need to increment hours
}

推荐答案

在您的尝试中，您错过了创建新数组的机会

In your attempt, you are missing out on creating a new array

var newArray = [];
var uniqueprojects = {};
for (var i =0; i<my_array.length; i++) {

   if ( !uniqueproject[my_array[i].Project] )
   {
     uniqueproject[my_array[i].Project] = 0;
   }
   uniqueproject[my_array[i].Project] += my_array[i].Hours;
   //my_array[i].Project   // access the object project key
   //my_array[i].Hours     // need to increment hours
}

现在从uniqueproject地图中创建最终的输出数组

Now create the final output array out of uniqueproject map

newArray = Object.keys(uniqueproject).map(function(key){return {Project:key, Hours:uniqueproject[key]}});

这篇关于在JavaScript中合并具有相同键的对象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IT屋！