如何在TypeScript上检查类中是否存在方法

class MyClass {
  myMethod() {
    console.log("Hello, world!");
  }
}

function hasMethod(obj: any, methodName: string): obj is { [key: string]: (...args: any[]) => any } {
  return typeof obj[methodName] === "function";
}

const myObj = new MyClass();

if (hasMethod(myObj, "myMethod")) {
  myObj.myMethod(); // 调用方法
} else {
  console.log("myMethod does not exist in MyClass");
}

class MyClass {
  myMethod?(): void;
}

const myObj = new MyClass();

if (myObj.myMethod) {
  myObj.myMethod(); // 调用方法
} else {
  console.log("myMethod does not exist in MyClass");
}