继承和类型判断

继承最好方法

var inherit = (function (c, p) {
    var F = function () { };
    return function (c, p) {
        F.prototype = p.prototype;
        c.prototype = new F();
        c.uber = p.prototype;
        c.prototype.constructor = c;
    }
})();

实现typeof

let class2type = {}
'Array Date RegExp Object Error'.split(' ').forEach(e => class2type['[object ' + e + ']'] = e.toLowerCase())

function type(obj) {
    if (obj == null) return String(obj)
    return typeof obj === 'object' ? class2type[Object.prototype.toString.call(obj)] || 'object' : typeof obj
}