【JavaScript】 模拟JQuery的连续调用函数

var zhangsan = {
    smoke: function () {
        console.log("Smoking...");
        return this;
    },
    drink: function () {
        console.log("drinking...");
        return this;
    },
    perm: function () {
        console.log("Perming...");
        return this;
    }
}

zhangsan.smoke().drink().perm();