1.當(dāng)一個(gè)對(duì)象的內(nèi)部狀態(tài)發(fā)生改變時(shí)掌唾，會(huì)導(dǎo)致其行為的而改變赡译，這看起來像是改變對(duì)象
對(duì)復(fù)雜的if else進(jìn)行抽取
function showResult(result){
if(result ==0){
console.log(1);
}else if(result ==1){
console.log(2);
}else if(result ==2){
console.log(3);
}
}
var Resutlstate= function(){
var states = {
state0: function(){
console.log(1)
},
state1: function(){
console.log(2)
},
state2: function(){
console.log(3)
},
state3: function(){
console.log(4)
},
state4: function(){
console.log(5)
}
}
function show(result){
states['state'+ result] && states['state'+ result]();
}
return {
show:show
}
}
