is

is 關(guān)鍵字為類型檢查關(guān)鍵字

重寫==

下面案例運(yùn)用了is關(guān)鍵字，檢查類型，并以判斷屬性值是否相等來檢查對象是否相等。

class Student{
  String name;
  int age;
  String school;

  Student.create(this.name,this.age,this.school);

  @override
  bool operator ==(other) {
    // 判斷是否是非
    if(other is! Student){
      return false;
    }
    final Student student = other;
    return name == student.name
        && age == student.age
        && school == student.school;
  }
}

void main(){
  Student studentA = Student.create('小白', 18, '南京大學(xué)');
  Student studentB = Student.create('小白', 18, '南京大學(xué)');
  print(studentA == studentB);
  // true
}