使用接口约束类型

interface Girl {
  name: string;
  age: number;
  bust: number;
}

const screenResume = (girl: Girl) => {
  girl.age < 24 && girl.bust >= 90 && console.log(girl.name + "进入面试");
  girl.age > 24 || (girl.bust < 90 && console.log(girl.name + "你被淘汰"));
};

const getResume = (girl: Girl) => {
  console.log(girl.name + "年龄是：" + girl.age);
  console.log(girl.name + "胸围是：" + girl.bust);
};
const girl = {
  name: "大脚",
  age: 18,
  bust: 94,
};

screenResume(girl);
getResume(girl);

接口和类型别名很像，但是类型别名可以直接给类型，比如string，而接口必须代表对象。

接口非必选值的定义

// 使用 ? 来标记可选值
interface Girl {
  name: string;
  age: number;
  bust: number;
  waistline?: number;
}
const getResume = (girl: Girl) => {
  console.log(girl.name + "年龄是：" + girl.age);
  console.log(girl.name + "胸围是：" + girl.bust);
  girl.waistline && console.log(girl.name + "腰围是：" + girl.waistline);
};

允许加入任意值

interface Girl {
  name: string;
  age: number;
  bust: number;
  waistline?: number;
  [propname: string]: any;
}
const girl = {
  name: "大脚",
  age: 18,
  bust: 94,
  waistline: 21,
  sex: "女",
};
const getResume = (girl: Girl) => {
  console.log(girl.name + "年龄是：" + girl.age);
  console.log(girl.name + "胸围是：" + girl.bust);
  girl.waistline && console.log(girl.name + "腰围是：" + girl.waistline);
  girl.sex && console.log(girl.name + "性别是：" + girl.sex);
};

接口里的方法

interface Girl {
  name: string;
  age: number;
  bust: number;
  waistline?: number;
  [propname: string]: any;
  say(): string;
}

const girl = {
  name: "大脚",
  age: 18,
  bust: 94,
  waistline: 21,
  sex: "女",
  say() {
    return "欢迎光临 ，红浪漫洗浴！！";
  },
};

接口和类的约束

class XiaoJieJie implements Girl {
  name = "刘英";
  age = 18;
  bust = 90;
  say() {
    return "欢迎光临 ，红浪漫洗浴！！";
  }
}

接口间的继承

interface Teacher extends Girl {
  teach(): string;
}

参考：
技术胖——TypeScript从入门到精通（08. TypeScript中的interface接口）
技术胖——TypeScript从入门到精通（09. TypeScript中的interface接口 2）