typeScript面试必备之-通识七:typeScript中的可索引接口（数组，对象）+类类型接口...-优快云博客

可索引接口：数组、对象的约束（不常用）
ts定义数组的方式

           var arr:number[]=[2342,235325]
            var arr1:Array<string>=['111','222']
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1.1可索引接口对数组的约束

  interface UserArr{
      [index:number]:string//表示定义的数组是key是number类型，value是string类型
  }
  var arr:UserArr=['aaa','bbb'];
  console.log(arr[0]);
  // var arr:UserArr=[123,'bbb'];  /*错误*/
  // console.log(arr[0]);
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1.2可索引接口对对象的约束

interface UserObj {
  [index: string]: string
}
var arr: UserObj = { name: '张三' };
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1.3类类型接口:对类的约束和抽象类抽象有点相似类类型接口中定义的不管是属性还是方法都要在子类中实现否则会报错！！！

interface Animal{
  name:string;
  eat(str:string):void;
}
class Dog implements Animal{
  name1:string;
  constructor(name:string){
      this.name1=name;
  }
  eat(){
      console.log(this.name1+'吃粮食')
  }
}
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正确写法

class Cat implements Animal{
  name:string;
  constructor(name:string){
      this.name=name;
  }
  eat(food:string){
      console.log(this.name+'吃'+food);
  }
}
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感谢：参考学习：https://www.itying.com：
自己总结到有道云笔记里面有更加清楚的标注方便查阅：
* Typescript 介绍
http://note.youdao.com/noteshare?id=c3e0d5810580041ade028a345519ce96&sub=E882CE350AC94C5596B146908C406274 * typeScript中的数据类型
http://note.youdao.com/noteshare?id=a07dd9a55779068d9409b79014a9a409&sub=CE3DA74B1A27412792DF9BB8F74E8E24 * typeScript中的函数
http://note.youdao.com/noteshare?id=adc64e95404f3c382c7549f05841c7b2&sub=65D365DE900049A28DD4697B61A5544A * 对象+继承
http://note.youdao.com/noteshare?id=7f82be21375761c13ccad1981510a614&sub=7856743A59934A59A1AA608AA78497F0 * 类的定义、继承、类里面的修饰符 http://note.youdao.com/noteshare?id=a4420ac729d8cc7c1eb72fc47198f00b&sub=399974DBD9FA4EC2A99548D8837CB61F * 静态属性静态方法抽象类多态
http://note.youdao.com/noteshare?id=efad91320514e4f21e07ec77a9bcfd7c&sub=DC3868B8459940CA884DC5B80EE25443
* typeScript中的接口
http://note.youdao.com/noteshare?id=ae4c7f13bec8e35b3fda4e326d7e7055&sub=6001FADE75904080A15395886608D366 * 可索引接口（数组，对象）+类类型接口
http://note.youdao.com/noteshare?id=aebf26ab922044a69cae082866ce8d86&sub=F73FB04DD10C4BA796173FBE40280B21
* 接口的继承、接口的扩展
http://note.youdao.com/noteshare?id=93e1dff481b8e299ee9c925e8e3a8b4a&sub=3C96456BFAA34C28BA6BB4E0B0C1E77B * 泛类
http://note.youdao.com/noteshare?id=6d9e0ec4cdb17249bf1bb11fae2e44ec&sub=B0C47B2089AC42E48C2E1BAAAD3FE9EF * 泛型接口
http://note.youdao.com/noteshare?id=49af2ba1bd6173467e7c7b844def959b&sub=F16F0C2857E347C0B8FB69522D5DEFA2