js 对象数组中相同的key ，value值相加

Question

var arry= [

    {key:'a',value:2},

    {key:'a',value:2},

    {key:'a',value:2},

    {key:'b',value:8}

]

期望得到结果：

var newArr =[

    {key:'a',value:6},

    {key:'b',value:8}

]

Answer 1

var array = [    {key: 'a', value: 2},    {key: 'a', value: 2},    {key: 'a', value: 2},    {key: 'b', value: 8}];var newArr = [{key:array[0].key, value: 0}];array.forEach((item, index)=>{    newArr.forEach((item2, index2) => {        if (item.key == item2.key) {            newArr[index2].value += item.value;        } else {            newArr.push(item);        }    })});console.log(newArr);

Answer 2

var arry= [    {key:'a',value:2},    {key:'a',value:2},    {key:'a',value:2},    {key:'b',value:8}]let result = {};array.forEach(item => {    if(result[item.key]){        result[item.key] += item.value;    }else{        result[item.key] = item.value;    }})let s = [];for(let k in result){    s.push({key:k,value:result[k]});}

Answer 3

Array.prototype.reduce 了解一下。array.reduce((resp, obj)=> {    var originObj = resp.find(item => item.key === obj.key);    if (originObj) {        originObj.value+= obj.value;    } else {        resp.push(obj)    }    return resp;}, [])

Answer 4

function keyPlusValue(arr) {  const result = arr.reduce((obj, item) => {    if (!obj[item.key]) {      obj[item.key] = 0    }    obj[item.key] += item.value    return obj  }, {})  return Object.keys(result).map(key => ({key: key, value: result[key]}))}console.log(keyPlusValue(arr))

Answer 5

这是我当时解决的方案var arry =[     {name:'a',value:2},     {name:'a',value:2},     {name:'a',value:2},     {name:'b',value:8}          ]        var temp = {};var data=[];        for(var i in arry) {            var key= arry[i].name;            if(temp[key]) {                temp[key].value = temp[key].value + arry[i].value;                temp[key].name = arry[i].name;            } else {                temp[key] = {};                temp[key].value = arry[i].value;                temp[key].name = arry[i].name;            }                    }        console.log(temp)

Answer 6

var newArr = [...arry.reduce((m, x) => m.set(x.key, (m.get(x.key) || 0) + x.value), new Map())]  .map(([key, value]) => ({ key, value }))

Answer 7

var arry= [        {key:'a',value:2},        {key:'a',value:2},        {key:'a',value:2},        {key:'b',value:8}    ]    let target = [];    let keysArr =[...new Set( arry.map(item=>item.key))]  ;    keysArr.forEach(item=>{       const  arr = arry.filter(keys=>keys.key == item);       const sum = arr.reduce((a,b)=>a+b.value,0)        target.push({            key:item,            value:sum        })    })    console.log(  target )