Scala do...while Loop


Unlike while loop, which tests the loop condition at the top of the loop, the do...while loop checks its condition at the bottom of the loop. A do...while loop is similar to a while loop, except that a do...while loop is guaranteed to execute at least one time.


The syntax of a do...while loop in Scala is:

}while( condition );

Notice that the conditional expression appears at the end of the loop, so the statement(s) in the loop execute once before the condition is tested. If the condition is true, the flow of control jumps back up to do, and the statement(s) in the loop execute again. This process repeats until the given condition becomes false.

Flow Diagram:

Scala do...while loop


object Test {
   def main(args: Array[String]) {
      // Local variable declaration:
      var a = 10;

      // do loop execution
         println( "Value of a: " + a );
         a = a + 1;
      }while( a < 20 )

When the above code is compiled and executed, it produces the following result:

C:/>scalac Test.scala
C:/>scala Test
value of a: 10
value of a: 11
value of a: 12
value of a: 13
value of a: 14
value of a: 15
value of a: 16
value of a: 17
value of a: 18
value of a: 19