JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr1 = ["how", "are", "you"],
    arr2 = ["how", "is", "it", "going"],
    count = 0;

    var count = 0;
    arr1.forEach(function (elem) {
        if (arr2.indexOf(elem) !== -1) {
            count++;
        }
    });

console.log(count);