鸿蒙学习笔记

第十二节 鸿蒙前置知识补充TS中的对象

语法于java比较相似

//定义枚举
enum Msg{
//与java枚举类似都是公开常量
    HI = 'Hi'
    HELLO = 'hello'
}

//定义接口抽象方法接受参数
interface A{
    say(msg:Msg):void
}
//定义类实现接口
class B implements A{
    say(msg:Msg):void{
        console.log(msg+"i am B")
    }
}

let a = new B()

a.say(Msg.HI)

-----------------------------------------------------
class Rectangle {
    private width:number
    private length:number
    constructor(width:number,length:number){
        this.width = width
        this.length = length
    }
    public area():number{
        return this.width*this.height
    }
}

class Square extends Rectangle{
    constructor(size:number){
        super(size,size)
    }
}

let s = new Square(5);
console.log(s.area())

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应用复杂的时候可以把通用功能抽取到单独的ts文件中，
每个文件是一个模块，模块之间可以相互加载

//定义矩形类
export class Rectangle {
    public width:number
    public length:number
    constructor(width:number,length:number){
        this.width = width
        this.length = length
    }
}
export function area(rec:Rectangle):number{
    return rec.width*rec.length
}
----
另外一个类
import {Rectangle,area} from '.../rectangle'

let r = new Rectangle(10,20)
console.log(area(r))