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command (命令)模式

通过简单的command(命令)模式,理解apply, call, 作用域

 (function(){        var carManager = {            requestInfo:function(model,id){                return ‘the infomation for ‘+model+‘ with ‘ + id+‘ is in foobar‘;            },            buyVehicle:function(model,id){                return ‘you hava successed buy  ‘+model+‘ with ‘ + id+‘ ‘;            },            arrangeViewing:function(){}        };        carManager.execute = function(name){            return carManager[name] && carManager[name].apply(carManager,[].slice.call(arguments,1));        };        carManager.execute(‘requestInfo‘,‘mini‘,‘1234‘);    })();

carManager[name] && carManager[name].apply(carManager,[].slice.call(arguments,1));

先从[].slice.call(arguments,1);开始说起,[]空数组使用slice方法,call(作用域,参数)。等于arguments.slice(1);并将结果返回到[]空数组里面。最后结果得到数组[‘mini‘,‘1234‘]

接着是carManager[name].apply(carManager,[‘mini‘,‘1234‘]);apply(作用域,参数(数组));将carManager[name]的作用域设置为(对象carManager),再把参数穿进去