check the difference between two arrays of objects in javascript

You can use filter to filter/loop thru the array and some to check if id exist on array 2

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 result = b1.filter(o => !b2.some(v => v.id === o.id));

console.log(result);

Above example will work if array 1 is longer. If you dont know which one is longer you can use sort to arrange the array and use reduce and filter.

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 result = [b1, b2].sort((a,b)=> b.length - a.length)
                     .reduce((a,b)=>a.filter(o => !b.some(v => v.id === o.id)));

console.log(result);

.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);

Tags:

Javascript

Arrays

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