nested for loops to get another object-array output-CodePudding

I need to multiply all the "values" inside "obj1" with the "percent' inside obj2 based on the id of each object. What would be the best way to do that? I've tried with for loop and reduce but I wasn't successful. Any help will be appreciated.

const obj1 = [ { id: 1, value: 10 }, { id: 2, value: 10 } ]

const obj2 = {
  len: {
      id: 1,
      nj: "321345", 
      percent: 0.05,
  },
  wor: {
      id: 2,
      nj: "321345", 
      percent: 0.1,
  }
}

outputExpected: [ { id: 1, value: 0.5 }, { id: 2, value: 1 } ]

CodePudding user response：

You can do that by going through and matching the ids. there are some optimizations that can be made if they are sorted however.

const obj1 = [ { id: 1, value: 10 }, { id: 2, value: 10 } ]

const obj2 = {
  len: {
      id: 1,
      nj: "321345", 
      percent: 0.05,
  },
  wor: {
      id: 2,
      nj: "321345", 
      percent: 0.1,
  }
}
const x = Object.keys(obj2).map((key,index)=>{
  const { id, value } = obj1.find(({id})=>id===obj2[key].id)
  return ({id,value:value*obj2[key].percent})
})
console.log(x)
//outputExpected: [ { id: 1, value: 0.5 }, { id: 2, value: 1 } ]

CodePudding user response：

This should work for you but doesnt handle exeptions if the id doesnt exist in both objects.

// First get the values in an array for easier manipulation
const aux = Object.values(obj2)

const output = obj1.map(ob => {
  // Find the id in the other array.
  const obj2Ob = aux.find(o => o.id === ob.id) // The id must exist in this aproach
  
  return {
    id: ob.id,
    value: ob.value * obj2Ob.percent
  }
})

console.log(output) // [ { id: 1, value: 0.5 }, { id: 2, value: 1 } ]

CodePudding user response：

You can first create a lookup map using Map, then loop over the obj1 using map to get the desired result

const obj1 = [
  { id: 1, value: 10 },
  { id: 2, value: 10 },
];

const obj2 = {
  len: {
    id: 1,
    nj: "321345",
    percent: 0.05,
  },
  wor: {
    id: 2,
    nj: "321345",
    percent: 0.1,
  },
};

const map = new Map();
Object.values(obj2).forEach((v) => map.set(v.id, v));

const result = obj1.map((o) => ({ ...o, value: o.value * map.get(o.id).percent }));

console.log(result);