How to find common elements only between 2 arrays in jquery [duplicate]

Answer 1

Here is my version

function diff(arr1, arr2) {
        var obj = {}, matched = [],
            unmatched = [];
        for (var i = 0, l = arr1.length; i < l; i++) {
            obj[arr1[i]] = (obj[arr1[i]] || 0) + 1;
        }
        for (i = 0; i < arr2.length; i++) {
            var val = arr2[i];
            if (val in obj) {
                matched.push(val);
            } else {
                unmatched.push(val);
            }
        }
        // Here you can find how many times an element is repeating.
        console.log(obj);
        // Here you can find what are matching.
        console.log(matched);
        // Here you can check whether they are equal or not.
        console.log('Both are equal ? :' + 
        matched.length === a.length);
        // Here you can find what are different  
        console.log(unmatched);
    }