几种常用设计模式

//工厂模式

function newObject(color,age,...arg){
let obj= new Object()
obj.color= color;
obj.age = age;
...arg;
return obj;
}

//单例模式
function getinstance=(function(){
let object;
return function(){
if(object ==undefined){
obj = new doSome()
return object;
}
}
})();
使用
let instance = getinstance()

//观察者模式

let mypromise = function(){
return new Promise((resolve,reject)=>{
if(true){
resolve(dosometing)
}else{
reject('error')
}

 }) 

}
//使用
mypromise.then(res=>{console.log(res)})

//策略模式
let object = {
"fist":function(){
dosmething;
},
"second":function(){
dosmething;
},
"thired":function(){
doSomething;
}
}
//代理模式

function isSend(message){
console.log(message+"目标对象")
}
function proxyObject(message){
let message = dosometing(message);
isSend(message)
}