static

class ClassWithStaticMethod {
  static staticProperty = "someValue";
  static staticMethod() {
    return "static method has been called.";
  }
  static {
    console.log("Class static initialization block called");
  }
}

console.log(ClassWithStaticMethod.staticProperty);
// Expected output: "someValue"
console.log(ClassWithStaticMethod.staticMethod());
// Expected output: "static method has been called."

class ClassWithStatic {
  static staticField;
  static staticFieldWithInitializer = value;
  static staticMethod() {
    // …
  }
}

class ClassWithStaticField {
  static staticField;
  static staticFieldWithInitializer = "静态字段";
}

class SubclassWithStaticField extends ClassWithStaticField {
  static subStaticField = "子类的字段";
}

console.log(Object.hasOwn(ClassWithStaticField, "staticField")); // true
console.log(ClassWithStaticField.staticField); // undefined
console.log(ClassWithStaticField.staticFieldWithInitializer); // "静态字段"
console.log(SubclassWithStaticField.staticFieldWithInitializer); // "静态字段"
console.log(SubclassWithStaticField.subStaticField); // "子类的字段"

class ClassWithStaticField {
  static baseStaticField = "基类静态字段";
  static anotherBaseStaticField = this.baseStaticField;

  static baseStaticMethod() {
    return "基类静态方法输出";
  }
}

class SubClassWithStaticField extends ClassWithStaticField {
  static subStaticField = super.baseStaticMethod();
}

console.log(ClassWithStaticField.anotherBaseStaticField); // "基类静态字段"
console.log(SubClassWithStaticField.subStaticField); // "基类静态方法输出"

class Triple {
  static customName = "三倍器";
  static description = "我可以让你提供的任何数变为它的三倍";
  static calculate(n = 1) {
    return n * 3;
  }
}

class SquaredTriple extends Triple {
  static longDescription;
  static description = "我可以让你提供的任何数变为其三倍的平方";
  static calculate(n) {
    return super.calculate(n) * super.calculate(n);
  }
}

console.log(Triple.description); // '我可以让你提供的任何数变为它的三倍'
console.log(Triple.calculate()); // 3
console.log(Triple.calculate(6)); // 18

let tp = new Triple();

console.log(SquaredTriple.calculate(3)); // 81（不会受父类实例化的影响）
console.log(SquaredTriple.description); // '我可以让你提供的任何数变为其三倍的平方'
console.log(SquaredTriple.longDescription); // undefined
console.log(SquaredTriple.customName); // '三倍器'

// 抛出错误，因为 calculate() 是静态成员，而不是实例成员。
console.log(tp.calculate()); // 'tp.calculate 不是一个函数'

class StaticMethodCall {
  static staticProperty = "静态属性";
  static staticMethod() {
    return `静态方法和${this.staticProperty}被调用`;
  }
  static anotherStaticMethod() {
    return `从另外一个静态方法而来的${this.staticMethod()}`;
  }
}
StaticMethodCall.staticMethod();
// '静态方法和静态属性被调用'

StaticMethodCall.anotherStaticMethod();
// '从另外一个静态方法而来的静态方法和静态属性被调用'

class StaticMethodCall {
  constructor() {
    console.log(StaticMethodCall.staticProperty); // '静态属性'
    console.log(this.constructor.staticProperty); // '静态属性'
    console.log(StaticMethodCall.staticMethod()); // '静态方法已调用'
    console.log(this.constructor.staticMethod()); // '静态方法已调用'
  }

  static staticProperty = "静态属性";
  static staticMethod() {
    return "静态方法已调用";
  }
}