javascript中相同对象名称的总和答案

【问题标题】：Sum of same object name in javascriptjavascript中相同对象名称的总和
【发布时间】：2017-01-24 09:25:28
【问题描述】：

嗨朋友们，我是 javascript 的初学者，我如何将相同的 n 对象名称对应值相加并将结果推送到新数组。看看这是示例对象

var obj_1 ={'delivered':10,'due':11,'team_name':'UK'}; var obj_2 ={'delivered':10,'due':11,'team_name':'US'}; var obj_nth ={'delivered':10,'due':11,'team_name':'UK'};

但我希望这个输出 [UK:{'delivered':20,'due':22},US:{'delivered':10,'due':11}]，所以请帮我下一步做什么

【问题讨论】：

这些对象是否存储在数组中？还是只是不同的变量？
放一些你试过的代码。
是的，那些 obj 存储在一个数组中

标签： javascript jquery json object

【解决方案1】：

您可以先创建对象数组，然后reduce() 返回一个对象。

var obj_1 ={'delivered':10,'due':11,'team_name':'UK'};
var obj_2 ={'delivered':10,'due':11,'team_name':'US'};
var obj_nth ={'delivered':10,'due':11,'team_name':'UK'};

var result = [obj_1, obj_2, obj_nth].reduce(function(r, e) {
  if(!r[e.team_name]) {
    r[e.team_name] = {delivered:0,due:0}
  }
  r[e.team_name].delivered += e.delivered
  r[e.team_name].due += e.due
  return r
}, {})

console.log(result)

【讨论】：

为什么是concat 而不仅仅是[o1, o2, o3]？

【解决方案2】：

const newArray = initialArray.map(({team_name, ...restProps}) => {
  return {
    [team_name]: {...restProps}
  };
});

见：

【讨论】：

【解决方案3】：

var obj_1 ={'delivered':10,'due':11,'team_name':'UK'};
var obj_2 ={'delivered':10,'due':11,'team_name':'US'};
var obj_nth ={'delivered':10,'due':11,'team_name':'UK'};

function sum_all() { 
    var sum={}; 
    for(var i=0;i<arguments.length;i++) { 
        obj = arguments[i]; 
        if (!sum[obj.team_name]) { 
            sum[obj.team_name]={'delivered':0,'due':0}; 
        } 
        sum[obj.team_name].delivered += obj.delivered; 
        sum[obj.team_name].due += obj.due;    
    } 
    return sum; 
}

var sum = sum_all(obj_1,obj_2,obj_nth);

console.log(sum);

您的控制台输出将是：

sum
Object
  UK: Object
      delivered: 20
      due: 22

  US: Object
      delivered: 10
      due: 11

【讨论】：

【解决方案4】：

将这些对象存储在array 中，例如：

var myObjects = [
    {'delivered':10,'due':11,'team_name':'UK'},
    {'delivered':10,'due':11,'team_name':'US'},
    {'delivered':10,'due':11,'team_name':'UK'}
];

创建一个用于存储结果的新对象：

var results = {};

然后用for循环（as it is generally faster）遍历数组，根据team_name添加其他属性：

for (var i = 0; i <= myObjects.length; i++) {
    if (typeof results[myObjects[i].team_name] !== undefined) {
        results[myObjects[i]].delivered += myObjects[i].delivered;
        results[myObjects[i]].due += myObjects[i].due; 
    } else {
        // Set 0 to these properties if the entry didn't exist
        results[myObjects[i]].delivered = 0;
        results[myObjects[i]].due = 0;
    }
}

【讨论】：