ts可索引接口类类型接口

可索引接口：数组、对象的约束（不常用）

var arr:number[]=[11, 22]
var arr:Array<string> = ['aa', 'bb']

可索引接口 对数组的约束

interface UserArr{
	[index:number]:string;
}
var arr:UserArr=['aa', 'bb']
console.log(arr[0])

可索引接口 对对象的约束

interface UserObj{
	[index:string]:string
}
var arr:UserObj = {
	name: 'alex'
}

类类型接口：对类的约束和抽象类有点相似

interface Animal{
	name:string;
	eat(val:string):void;
}

class Dog implemenets Animal{
	name:string
	constructor(name:string){
		this.name = name
	}
	eat(){
		console.log(`${this.name}吃骨头`)
	}
}

class Cat implements Animal{
	name: string
	constructor(name:string){
		this.name = name
	}
	eat(){
		console.log(`${this.name}吃鱼`)
	}
}
var d = new Dog('狗子')
d.eat()

var c = new Cat('猫')
c.eat()