how to compare elements of an array javascript code example

Example 1: javascript compare two arrays of objects get same elements

var result = result1.filter(function (o1) {
    return result2.some(function (o2) {
        return o1.id === o2.id; // return the ones with equal id
   });
});
// if you want to be more clever...
let result = result1.filter(o1 => result2.some(o2 => o1.id === o2.id));

Example 2: compare arrays javascript

// For regular 1D array
const array1 = [1,2,3,4]
const array2 = [1,2,3,4]

array1.join() === array2.join()
// '1,2,3,4' === '1,2,3,4'

// For anything more complex
const array3 = [1,2,3,[1,2,3]]
const array4 = [1,2,3,[1,2,3]]

JSON.stringify(array3) === JSON.stringify(array4)