是否构成三角形

scala
object w20 {

  class Triangle(var a: Double = 1.0, var b: Double = 1.0, var c: Double = 1.0) {
    println(s"Triangle(${a},${b},${c})")
    def check(): Boolean = {
      return a + b > c && b + c > a && a + c > b
    }
  }

  def main(args: Array[String]): Unit = {
    print("请输入第一条边")
    val a = scala.io.StdIn.readDouble()
    print("请输入第二条边")
    val b = scala.io.StdIn.readDouble()
    print("请输入第三条边")
    val c = scala.io.StdIn.readDouble()

    val t1 = new Triangle(a, b, c)

    if (t1.check()) {
      println("能构成三角形")
    } else {
      println("不能构成三角形")
    }
  }
}

scala
object w22 {

  class Student(var name:String, var age:Int, var gender:String="男", var nav:String="汉族") {
    def say(): Unit = {
      println(s"${name}, ${age}, ${gender}, ${nav}")
    }
  }
  def main(args: Array[String]): Unit = {
    var s1 = new Student("小明", 19)
    s1.say()
    var s2 = new Student("樊振东", 28, "男", "汉族")
    s2.say()
  }
}

scala
object w21 {
  class Triangle(var a: Double = 1.0, var b: Double = 1.0, var c: Double = 1.0) {
    println(s"Triangle(${a}, ${b}, ${c})")
    def check(): Boolean = {
      return a + b > c && b + c > a && a + c > b
    }
    def getArea(): Double = {
      if (check()) {
        var s = (a + b + c) / 2
        return Math.sqrt(s * (s - a) * (s - b) * (s - c))
      } else {
        println(s"${a}, ${b}, ${c} 不能构成一个三角形")
        return -1
      }
    }
  }
  def main(args: Array[String]): Unit = {
    val t1 = new Triangle(3, 4, 7)
    println(t1.getArea())
    val t2 = new Triangle(3, 4, 3)
    println(t2.getArea())
  }
}