scala构造函数

//默认主构造函数
class Student {
  println("hello from default constructor!!!")
}

//主构造函数
class Student1(id:Int,name:String){
  def showDetails(): Unit ={
    println(id + " " + name)
  }
}

//次要/辅助构造器
class Student2(id:Int,name:String){
  var age:Int = 16
  def this(id:Int,name:String,age:Int){
    this(id,name)
    this.age = age
    println(id + "|" + name + "|" + age)
  }
  println(id + "--" + name)
  def showDetails(): Unit ={
    println(id + " " + name + " " + age)
  }
}

object test1{
  def main(args: Array[String]): Unit = {
    println("---默认主构造函数---")
    new Student()
    println("---主构造函数---")
    val s1 = new Student1(16,"xl")
    s1.showDetails()
    println("---辅助构造函数和构造器重载---")
    val s2 = new Student2(21,"xll",18)
    s2.showDetails()
    println("----------------")
    val s22 = new Student2(22,"xlll")
    s22.showDetails()
  }
}

---默认主构造函数---
hello from default constructor!!!
---主构造函数---
16 xl
---辅助构造函数和构造器重载---
21--xll
21|xll|18
21 xll 18
----------------
22--xlll
22 xlll 16