LeetCode/js/check-if-object-instance-of-class.js

/**
 * @param {any} obj
 * @param {any} classFunction
 * @return {boolean}
 */
var checkIfInstanceOf = function(obj, classFunction) {
    if (obj === null || obj === undefined || typeof classFunction !== "function") {
        return false;
    }

    return Object(obj) instanceof classFunction;
};

/**
 * checkIfInstanceOf(new Date(), Date); // true
 */