循环遍历两个数组并根据条件更改属性值不起作用

Question

I have two arrays with some common property. I use filter and if Id is equal then change one of the value, here for example email. I use spread operator for the same. But it is not working. However when I console log before returning it shows the update value. Also if I change using assignment operator then its working. Can somebody let me know why is spread operator not working or I am missing some concept. Below is sample code

var result1 = [
  {id:1, name:'Sandra', type:'user', username:'sandra'},
  {id:2, name:'John', type:'admin', username:'johnny2'},
  {id:3, name:'Peter', type:'user', username:'pete'},
  {id:4, name:'Bobby', type:'user', username:'be_bob'}
];

var result2 = [
  {id:2, name:'John', email:'johnny@example.com',fullName:'Test1'},
  {id:4, name:'Bobby', email:'bobby@example.com',fulname:'Test2'}
];

var result = result2.filter(function(x){
  return result1.filter(function(y){
      if(x.id === y.id){
        console.log( {...x,email:y.name})
        return {...x,email:y.name}
        // x.email=y.name
      }     
  });
})
console.log(result)

Answer 1

The filter function should return a boolean and it's not meant to edit objects.
Try to map the first array and find their values in the other, if the value is present return the edited object:

 var result1 = [ { id: 1, name: 'Sandra', type: 'user', username: 'sandra' }, { id: 2, name: 'John', type: 'admin', username: 'johnny2' }, { id: 3, name: 'Peter', type: 'user', username: 'pete' }, { id: 4, name: 'Bobby', type: 'user', username: 'be_bob' }, ]; var result2 = [ { id: 2, name: 'John', email: 'johnny@example.com', fullName: 'Test1' }, { id: 4, name: 'Bobby', email: 'bobby@example.com', fulname: 'Test2' }, ]; const result = result2.map((x) => { const y = result1.find(value => x.id === value.id); if (y) return { ...x, email: y.name }; return x; }) console.log(result);