Scala do…while cycle

Not like the while loop tests the loop condition in the loop header, inthe Scala language do...while a loop checks its condition at the end of the loop.

do...while cycle and the while loop is similar, but the do...while loop ensures that the loop is executed at least once.

Grammar

In Scala language the while syntax of the loop:

do {
   statement(s);
} while( condition );

Flow chart

Notice that the conditional expression appears at the end of the loop, so the statement(s) will be executed at least once before the conditionis tested.

If the condition is the true control flow will jump back to the above do and then re-execute the statement(s) .

This process is repeated over and over again until a given condition becomes``false`` so far.

Example

object Test {
   def main(args: Array[String]) {
      // local variable
      var a = 10;
      // do loop
      do{
         println( "Value of a: " + a );
         a = a + 1;
      }while( a < 20 )
   }
}

The output result of executing the above code is:

$ scalac Test.scala
$ 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