Guards और Binding

object Main {
  def sign(n: Int): String = n match {
    case x if x > 0 => "positive"
    case x if x < 0 => "negative"
    case _          => "zero"
  }
  def main(args: Array[String]): Unit = {
    println(sign(5))
    println(sign(-3))
    println(sign(0))
  }
}

object Main {
  def fizz(n: Int): String = n match {
    case x if x % 15 == 0 => "FizzBuzz"
    case x if x % 3 == 0  => "Fizz"
    case x if x % 5 == 0  => "Buzz"
    case x                => x.toString
  }
  def main(args: Array[String]): Unit = {
    println(fizz(15))
    println(fizz(9))
    println(fizz(7))
  }
}

object Main {
  def band(score: Int): String = score match {
    case s if s >= 90 => "A"
    case s if s >= 80 => "B"
    case s if s >= 70 => "C"
    case _            => "F"
  }
  def main(args: Array[String]): Unit = {
    println(band(95))
    println(band(83))
    println(band(60))
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val x: Any = 7
    val msg = x match {
      case n @ (_: Int) => s"int value is $n"
      case _            => "other"
    }
    println(msg)
  }
}

object Main {
  def describe(xs: List[Int]): String = xs match {
    case all @ (first :: _) => s"starts with $first, full = $all"
    case Nil                => "empty"
  }
  def main(args: Array[String]): Unit = {
    println(describe(List(1, 2, 3)))
    println(describe(Nil))
  }
}

object Main {
  def label(x: Any): String = x match {
    case s: String if s.length > 3 => "long string"
    case s: String                 => "short string"
    case _                         => "not a string"
  }
  def main(args: Array[String]): Unit = {
    println(label("hello"))
    println(label("hi"))
    println(label(42))
  }
}

object Main {
  def category(age: Int): String = age match {
    case a if a >= 13 && a <= 19 => "teen"
    case a if a < 13             => "child"
    case _                       => "adult"
  }
  def main(args: Array[String]): Unit = {
    println(category(15))
    println(category(8))
    println(category(40))
  }
}

object Main {
  def test(n: Int): String = n match {
    case x if x > 100 => "big"
    case x            => s"not big: $x"
  }
  def main(args: Array[String]): Unit = {
    println(test(200))
    println(test(5))
  }
}

object Main {
  def temp(c: Int): String = c match {
    case t if t >= 30 => s"hot ($t)"
    case t if t >= 15 => s"mild ($t)"
    case t            => s"cold ($t)"
  }
  def main(args: Array[String]): Unit = {
    println(temp(35))
    println(temp(20))
    println(temp(5))
  }
}