Best JavaScript Array Detection Technique

isarray.js

/**
 * Check whether an object is Array or not
 * @type Boolean
 * @param {object} subject is the variable that is
 * tested for Array identity check
 */
var isArray = (function () {
    // Use browser's own `isArray` when available
    if (Array.isArray) {
        return Array.isArray;
    }

    // Retain references to variables for performance optimization
    var objToStringFn = Object.prototype.toString,
        arrToStringResult = objToStringFn.call([]);

    // Use object prototype's toString method as comparison
    return function (subject) {
        return objToStringFn.call(subject) === arrToStringResult;
    };
}());