SO-33461584

by David Thomas

JavaScript

// extending the prototype of the Array,
// with a named method/function:
Array.prototype.commonElements = function (arr2) {

    // iterating over the 'this' array:
    return this.some(function (el) {

        // looks for the array-value
        // represented by 'el', and
        // comparing the returned index
        // to see if it's greater than
        // -1 (and so is found in 'this' array):
        return arr2.indexOf(el) > -1;
    });
}

var one = [1, 2, 3, 4, 5],
    two = [5, 6, 7, 8, 9];

console.log(one.commonElements(two)); // true