补2

1.1

object base12 {
  def main(args: Array[String]): Unit = {
    // 精度
    val a = 0.1 + 0.2 == 0.3
    val b = 0.2 + 0.2 == 0.4
    val c = BigDecimal(0.1) + BigDecimal(0.2) == BigDecimal(0.3)
    println(a)
    println(b)
    println(c)
  }

}

1.2

object base13 {
    def main (args: Array [String]) = {
     // 一个字符串，表示数字的字符串
         var a = BigInt("11111")
         var b = BigInt("22222")
         var c = a*b
        println(c)

    }
}

1.3 scala case object base14 { def main (args: Array [String]): Unit= {

print ("请输入你的年龄:")
var age = scala.io.StdIn.readInt ()

if(age >= 18){
  println ("成年人")
} else {
  println ("未成年人")
}

} }