高阶函数

定义：能够包装函数的，使原本函数增加一些额外的福利的函数

比如： function higherOrderFn(fn){} 能够对fn增加一些额外的福利

应用场景：

(function () {
        var getLogin = function () {
            var a = parseInt((Math.random() * 10).toFixed(0));
            if (a % 2 == 0) {
                return {
                    login: false
                }
            }
            return {
                login: true,
                userInfo: {
                    vip: 11,
                    nickname: 'jake',
                    userid: '888888888'
                }
            }
        }
        var withLogin = function (basicFn) {
            var loginInfo = getLogin();
            return basicFn.bind(null, loginInfo);
        }
        window.withLogin = withLogin;
    }

)()


(function () {
    var withLogin = window.withLogin;
    var renderIndex = function (loginInfo) {
        if (loginInfo.login) {
            console.log('login success render main page');
        } else {
            console.log('login failed render main page');
        }
    }

    window.renderIndex = withLogin(renderIndex);
}

)();

(function () {
    var withLogin = window.withLogin;
    var renderPersonalIndex = function (loginInfo) {
        if (loginInfo.login) {
            console.log('login success render personal page');
        } else {
            console.log('login success render personal page');
        }
    }

    window.renderPersonalIndex = withLogin(renderPersonalIndex);
}

)()

(function () {
   window.renderIndex();
})()

 

来源：oschina

链接：https://my.oschina.net/u/2285087/blog/3159965