Scala笔记——类型检查和转换

1. A.isInstanceOf[T]：判断对象A是不是T类型
2. A.asInstanceOf[T]：将对象A强转成T类型
3. classOf获取对象的类名 ```scala package test

object test { def main(args: Array[String]): Unit = { val student1: Student = new Student(“fyl”, 18) val person1: Person = new Student(“abc”, 18) val person2: Person = new Person(“bbb”,20)

//类型检测
println("student1 is Student: " + student1.isInstanceOf[Student]) //true
println("student1 is Person: " + student1.isInstanceOf[Person]) //true
println("person1 is Person: " + person1.isInstanceOf[Person]) //true
println("person1 is Student: " + person1.isInstanceOf[Student]) //true
println("person2 is Student: " + person2.isInstanceOf[Student]) //false
//类型转换
if (person1.isInstanceOf[Student]){
  val newStudent = person1.asInstanceOf[Student]
  println(classOf[Student])   //class test.test$Student
  newStudent.study()    //student study
}

}

class Person(val name: String, val age: Int) { def sayHi(): Unit = { println(“hi from person” + name) } }

class Student(name: String, age: Int) extends Person(name, age) { override def sayHi(): Unit = { println(“hi from person” + name) }

def study() = {
  println("student study")
}

} }

```