js 状态模式

状态模式：解决多个分支判断时代码臃肿问题，以及状态间的耦合，便于增删改查。

var rewards=['奖品1','奖品2','奖品3','奖品4','奖品5','奖品6'];
var touzi=(function () {
    var result=Math.floor(Math.random()*6+1);
    return{
        res:result
    }
})();
(function (endRes) {
    if (endRes===1){
        console.log('您获得了'+rewards[0]);
    }else if(endRes===2){
        console.log('您获得了'+rewards[1]);
    }else if(endRes===3){
        console.log('您获得了'+rewards[2]);
    }else if(endRes===4){
        console.log('您获得了'+rewards[3]);
    }else if(endRes===5){
        console.log('您获得了'+rewards[4]);
    }else if(endRes===6){
        console.log('您获得了'+rewards[5]);
    }
})(touzi.res)


更清爽的

var State=function () {
    var States={
        state0:function (i) {
            alert('state0')
        },
        state1:function (i) {
            alert('state1')
        },
        state2:function (i) {
            alert('state2')
        },
        state3:function (i) {
            alert('state3')
        }
    };
    function getRes(res) {
        States['state'+res] && States['state'+res]();
    }
    return{
        setState:getRes
    }
}();
    State.setState(0)

log函数监控操作

var log=(function () {
    var info="";
    return{
        set:function (msg) {
            info+=msg+"\n"
        },
        getAll:function () {
            console.log(info);
            info=""
        }
    }
})();

var ThingState=function () {
    var _needState={};
    states={
        state0:function () {
            log.set('state0 -> 一等奖')
        },
        state1:function () {
            log.set('state1 -> 二等奖');
        },
        state2:function () {
            log.set("state2 -> 三等奖");
        }
    };
    var Action={
        addStates:function () {
            var arg=arguments;
            _needState={};
            if(arg.length){
                for(var i=0,l=arg.length;i<l;i++){
                    _needState[arg[i]]=true
                }
            }
            return this;
        },
        mission:function () {
            for(key in _needState){
                states[key] && states[key]();
            }
            return this
        }
    };
    return{
        addStates:Action.addStates,
        mission:Action.mission
    }
};

var mac=new ThingState();
mac.addStates('state0','state1')
    .mission()
    .addStates('state2')
    .mission();
log.getAll();