//############################################################################ // 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): Unit = { 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]): Unit = { check_success("Test1", Test1.run, 1); check_success("Test2", Test2.run, 0); Console.println; } } //############################################################################