check the difference between two arrays of objects in javascript

Question

I need some help. How can I get the array of the difference on this scenario:

var b1 = [
  { id: 0, name: 'john' }, 
  { id: 1, name: 'mary' }, 
  { id: 2, name: 'pablo' }, 
  { id: 3, name: 'escobar' } 
]; 

var b2 = [
  { id: 0, name: 'john' }, 
  { id: 1, name: 'mary' }
];

I want the array of difference:

// [{ id: 2, name: 'pablo' }, { id: 3, name: 'escobar' }]

How is the most optimized approach?

I′m trying to filter a reduced array.. something on this line:

var Bfiltered = b1.filter(function (x) {
return x.name !== b2.reduce(function (acc, document, index) {
    return (document.name === x.name) ? document.name : false
},0)

});

console.log("Bfiltered", Bfiltered);
// returns { id: 0, name: 'john' }, { id: 2, name: 'pablo' }, { id: 3, name: 'escobar' } ]

Thanks,

Robot

Answer 1

.Filter() and .some() functions will do the trick

var b1 = [
  { id: 0, name: 'john' }, 
  { id: 1, name: 'mary' }, 
  { id: 2, name: 'pablo' }, 
  { id: 3, name: 'escobar' } 
]; 

var b2 = [
  { id: 0, name: 'john' }, 
  { id: 1, name: 'mary' }
];

var res = b1.filter(item1 => 
!b2.some(item2 => (item2.id === item1.id && item2.name === item1.name)))

console.log(res);