my problem is to map two array of objects and sum their specifics properties if they have same name value.

For example if I would like to sum x and y of all objects where property name is 'v' etc. Here is my code

var arr = [{name:'v', x:1, b:2, c:3},{name:'r', x:2, b:0, c:3},{name:'v', x:4, b:3, c:3}, {name:'v', x:1, b:1, c:3}];
let arr2 = []
let obj = {name:null, x:null, b: null, c:null}
arr.map(item => {
for(let i=0; i<= arr.length; i  ){

    if(item.name === arr[i].name){
     let a = arr.reduce((a, b) => ({x: a.x   b.x, b: a.b   b.b})); 
      obj.name = item.name, obj.x = a.x, obj.b = a.b, obj.c = item.c
    } else {
    obj.name = item.name, obj.x=item.x, obj.b=item.b, obj.c=item.c
        }
  arr2.push(obj)
        }
  }
)

console.log(arr2)

As result i would like to return array like this

arr2 = [{name: 'v', x: 6, b: 6, c: 3}, {name: 'r', x:2, b:0, c:1}]

CodePudding user response：

const sumProperties = (arr) => {
  const result = [];
  const map = new Map();
  for (const obj of arr) {
    const key = obj.name;
    if (!map.has(key)) {
      map.set(key, obj);
    } else {
      const oldObj = map.get(key);
      const newObj = { ...oldObj, ...obj };
      map.set(key, newObj);
    }
  }
  map.forEach((value) => {
    result.push(value);
  });
  return result;
}
console.log(sumProperties(arr));

CodePudding user response：

First I ran reduce over your array and got an intermediate result in the format below.

{
  r: {
    b: 0,
    c: 3,
    name: "r",
    x: 2
  },
  v: {
    b: 6,
    c: 3,
    name: "v",
    x: 6
  }
}

Then since your expected result is the values of the intermediate result I called Object.values which returns an array of the values

let arr = [{name:'v', x:1, b:2, c:3},{name:'r', x:2, b:0, c:3},{name:'v', x:4, b:3, c:3}, {name:'v', x:1, b:1, c:3}];

let a = arr.reduce((acc,curr)=>{
  if(!acc[curr.name]){
    acc[curr.name]={name:curr.name,x:0, b:0, c:curr.c}
  }
  let keyArr = Object.keys(curr);
    keyArr.forEach((k)=>{
    if(k!=="name" && k!=="c"){
        acc[curr.name][k] =curr[k]
    }
  })
  return acc;
  
},{})

let result = Object.values(a)


console.log(result)

CodePudding user response：

Here is the answer for my question

var arr = [{v:'v', x:1, b:2, c:3},{v:'r', x:2, b:0, c:3},{v:'v', x:4, b:3, c:3},{v:'v', x:10, b:3, c:3},{v:'r', x:1, b:1, c:3},{v:'v', x:11, b:2, c:3},{v:'r', x:22, b:0, c:3}];
let arr2 = []
for(let j=0; j< arr.length;j  ){
    for(let i=j 1; i< arr.length; i  ){
        let obj = {v:null, x:null, b: null, c:null}
        if(arr[j].v === arr[i].v ){
          let a =  arr.filter(({v})=> v === arr[j].v).reduce((a, b) => ({x: a.x   b.x, b: a.b   b.b})); 
        obj.v = arr[j].v
        obj.x = a.x 
        obj.b = a.b 
        obj.c = arr[j].c  
        i= arr.length
        console.log("DA", obj)
        if(!arr2.some(item=> item.v === obj.v)){
            arr2.push(obj)
        }
    } else if(i 1 === arr.length){  
        obj.v = arr[j].v 
        obj.x = arr[j].x 
        obj.b = arr[j].b 
        obj.c = arr[j].c
        console.log("NE", obj)
        if(!arr2.some(item=> item.v === obj.v)){
            arr2.push(obj)
            }
        }
    }
}
console.log(arr2, "REZ")