Question

嗨，我有以下JSON对象；

var obj1 = {"a":1,"b":1,"c":1};
var obj2 = {"a":2,"b":2,"c":2};
var obj3 = {"a":3,"b":3,"c":3};

我想相加或减去3个json对象我希望最终结果为

  {"a":6,"b":6,"c":6}

我知道使用不同类型的循环非常简单。但是我想知道javascript中是否存在任何功能来合并多个JSON对象并添加或减去每个属性（无循环）。

在数组中是否有像reduce这样的函数：如下所示：

var squares = arr.concat(arr2).reduce((t,n)=>t+n);

谢谢

Answer 1

没有这样的内置函数可以自动完成类似的任务，但是编写自己的代码来实现所需功能很简单：

var obj1 = {"a":1,"b":1,'c':1};
var obj2 = {"a":2,"b":2,'c':2};
var obj3 = {"a":3,"b":3,'c':3};
const combined = [obj1, obj2, obj3].reduce((a, obj) => {
  Object.entries(obj).forEach(([key, val]) => {
    a[key] = (a[key] || 0) + val;
  });
  return a;
});
console.log(combined);

Answer 2

您可以仅遍历object个属性之一并构造结果：

let res = {};
for (p in obj1) {
  res[p] = obj1[p] + (obj2[p] || 0) + (obj3[p] || 0);
}

演示：

var obj1 = {"a":1,"b":1,"c":1};
var obj2 = {"a":2,"b":2,"c":2};
var obj3 = {"a":3,"b":3,"c":3};

let res = {};

for (p in obj1) {
  res[p] = obj1[p] + (obj2[p] || 0) + (obj3[p] || 0);
}
console.log(res);

如何将两个或多个JSON对象汇总为一个

2 个答案: