合并具有相同键值的 JavaScript 对象并对其进行计数
javascriptweb developmentfront end technologyobject oriented programming
假设，我们有一个像这样的对象数组 −
const arr = [{
"value": 10,
"id": "111",
"name": "BlackCat",
}, {
"value": 10,
"id": "111",
"name":
"BlackCat",
}, {
"value": 15,
"id": "777",
"name": "WhiteCat",
}];
我们需要编写一个 JavaScript 函数来接收一个这样的数组。
然后，该函数应将所有具有"id"属性共同值的对象合并在一起。
因此，对于上述数组，输出应如下所示 −
const output = [{
"value": 10,
"id": "111",
"name": "BlackCat",
"count": 2,
}, {
"value": 15,
"id": "777",
"name": "WhiteCat",
"count": 1,
}]
示例
const arr = [{
"value": 10,
"id": "111",
"name": "BlackCat",
}, {
"value": 10,
"id": "111",
"name": "BlackCat",
}, {
"value": 15,
"id": "777",
"name": "WhiteCat",
}];
const combinedItems = (arr = []) => {
const res = arr.reduce((acc, obj) => {
let found = false;
for (let i = 0; i < acc.length; i++) {
if (acc[i].id === obj.id) {
found = true;
acc[i].count++;
};
}
if (!found) {
obj.count = 1;
acc.push(obj);
}
return acc;
}, []);
return res;
}
console.log(combinedItems(arr));
输出
控制台中的输出将是 −
[
{ value: 10, id: '111', name: 'BlackCat', count: 2 },
{ value: 15, id: '777', name: 'WhiteCat', count: 1 }
]
