Question

I have two arrays of objects like this:

var arr1 = [{Id: 1, Name: "Test1"}, {Id: 2, Name: "Test2"}, {Id: 3, Name: "Test3"}, {Id: 4, Name: "Test4"}]

var arr2 = [{Id: 1, Name: "Test1"}, {Id: 3, Name: "Test3"}]

I need to compare the elements of the two arrays by Id and remove the elements from arr1 that are not presented in arr2 ( does not have element with that Id). How can I do this ?

Answer 1

You can use a function that accepts any number of arrays, and returns only the items that are present in all of them.

function compare() {
    let arr = [...arguments];
    return arr.shift().filter( y => 
        arr.every( x => x.some( j => j.Id === y.Id) )
    )
}

var arr1 = [{Id: 1, Name: "Test1"}, {Id: 2, Name: "Test2"}, {Id: 3, Name: "Test3"}, {Id: 4, Name: "Test4"}];
var arr2 = [{Id: 1, Name: "Test1"}, {Id: 3, Name: "Test3"}, {Id: 30, Name: "Test3"}];
var arr3 = [{Id: 1, Name: "Test1"}, {Id: 6, Name: "Test3"}, {Id: 30, Name: "Test3"}];

var new_arr = compare(arr1, arr2, arr3);
console.log(new_arr);

function compare() {
	let arr = [...arguments]
	
	return arr.shift().filter( y => 
  	arr.every( x => x.some( j => j.Id === y.Id) )
  )
}