4JavaScript设计模式--工厂模式/单例模式/适配器模式

• 工厂模式

 

class Product{
    constructor(name){
        this.name = name
    }
    init(){
        console.log('init')
    }
    fn1(){
        console.log('fn1')
    }
    fn2(){
        console.log('fn2')
    }
}
class Creator{
    creater(name){
        return new Product(name)
    }
}

let creater = new Creator()
let p = creater.creater('apple')
p.init()
p.fn1()
p.fn2()

• 单例模式

演示代码

class SingleObject{
    login(){
        console.log('login...')
    }
}
//定义的静态方法
SingleObject.getInstance = (function(){
    let instance
    return function(){
        if(!instance){
            instance = new SingleObject()
        }
        return instance
    }
}())

let obj1 = SingleObject.getInstance()
obj1.login()
let obj2 = SingleObject.getInstance()
obj2.login()
console.log('obj1 === obj2',obj1 === obj2) //obj1 === obj2 true

//直接使用SingleObject，则不属于单例模式。在ES6中很难避免该错误用法。TS中可以实现
let obj3 = new SingleObject()
obj3.login()
console.log('obj3 === obj2',obj3 === obj2)

• 适配器模式

方法