TypeScript接口Interface详解：定义对象类型的核心工具

interface Person {
  name: string;
  age: number;
}

function greet(person: Person) {
  console.log(`Hello, ${person.name}!`);
}
const john: Person = { name: "John", age: 30 };
greet(john); // 输出: Hello, John!

interface Car {
  brand: string;
  model: string;
  year?: number;
}
const myCar: Car = { brand: "Toyota", model: "Corolla" };

interface Point {
  readonly x: number;
  readonly y: number;
}
const point: Point = { x: 10, y: 20 };
// point.x = 5; // 错误:无法分配到 "x" ,因为它是只读属性

interface MathFunc {
  (x: number, y: number): number;
}
const add: MathFunc = (a, b) => a + b;

interface StringArray {
  [index: number]: string;
}
const myArray: StringArray = ["Apple", "Banana", "Cherry"];
console.log(myArray[1]); // 输出: Banana

interface Shape {
  color: string;
}
interface Square extends Shape {
  sideLength: number;
}
const square: Square = { color: "blue", sideLength: 10 };

interface Printable {
  print(): void;
}
class Book implements Printable {
  title: string;
  constructor(title: string) {
    this.title = title;
  }
  print() {
    console.log(`Printing: ${this.title}`);
  }
}

interface Counter {
  (start: number): string;
  interval: number;
  reset(): void;
}
function getCounter(): Counter {
  let counter = function (start: number) {} as Counter;
  counter.interval = 123;
  counter.reset = function () {};
  return counter;
}

interface Box {
  height: number;
  width: number;
}
interface Box {
  scale: number;
}
const box: Box = { height: 5, width: 6, scale: 10 };