Scala example source code file (boolexprs.scala)

This example Scala source code file (boolexprs.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

array, boolean, counter, counter, int, int, string, test, test1, test1, test2, test2, throwable

The Scala boolexprs.scala source code

//############################################################################
// Boolean Expressions
//############################################################################

class Counter {
  private var n: Int = 0;
  def incrThen(b: Boolean) = if (b) n += 1;
  def value = n;
}

object Test1 {
  var flag = false;
  def flip: Boolean = { val tmp = flag; flag = !flag; tmp } 
  def run: Int = {
    val c = new Counter;
    c.incrThen(flip || flip);
    c.value
  }
}

object Test2 {
  val a = Array(false);

  def run: Int = {
    val c = new Counter;
    c.incrThen(true && a(0));
    c.incrThen(false || Nil.length > 0);
    c.value
  }
}

//############################################################################
// Test code

object Test {
  def check_success(name: String, closure: => Int, expected: Int) {
    Console.print("test " + name);
    try {
      val actual: Int = closure;
      if (actual == expected) {
        Console.print(" was successful");
      } else {
        Console.print(" failed: expected "+ expected +", found "+ actual);
      }
    } catch {
      case exception: Throwable =>
        Console.print(" raised exception " + exception);
    }
    Console.println;
  }

  def main(args: Array[String]) {
    check_success("Test1", Test1.run, 1);
    check_success("Test2", Test2.run, 0);
    Console.println;
  }
}

//############################################################################