TypeScript-接口

属性接口

interface PersonInfo {
  firstName: string;
  secondName?: string;// 可选属性
}

function printName(info: PersonInfo) {
  console.log(info.firstName + info.secondName);
}

printName({
  firstName: 'zhang',
});

函数类型接口

interface encrypt {
  (key: string, value: string): string;
}

let md5: encrypt = function (key: string, value: string): string {
  return key + value;
};

可索引接口

对数组约束

interface UserArr {
  [index: number]: string;
}

let arr1: UserArr = ['aaa'];

对对象约束

interface UserObj {
  [index: string]: string;
}

let obj: UserObj = {name: 'aaa'};

类类型接口

与抽象类类似

interface UserAnimal {
  name: string;

  eat(str: string): void;
}

class UserDog implements UserAnimal {
  name: string;

  constructor(name: string) {
    this.name = name;
  }

  // 参数可选
  eat(): void {
    console.log(this.name);
  }
}

接口的扩展

可继承

interface food {
  eat(): void;
}

interface Banana extends food {
  work(): void;
}