While is a loop that is executed as long as a condition is true. It has the following two syntaxes:

while(condition) exprToBeExecuted;
doexprToBeExecuted while(condition);

With the first syntax, the condition is tested before entering the loop. That means, if the condition is not true, exprToBeExecuted will never be executed.

With the second syntax, the condition is tested after the execution of exprToBeExecuted. This way, you are sure that exprToBeExecuted will be executed at least once. The following are two simple examples to help you understand how these syntaxes have to be used:

public static function main()
{
   var i : Int = 0;
   while(i< 18)
   {
      trace(i); //Will trace numbers from 0 to 17 included
      i++;
   }
}

The preceding code is for the first syntax, and now, the second syntax:

public static function main()
{
   var i : Int = 0;
   do
   {
      trace(i); //Will...