WHILE

The WHILE statement executes a block of statements until the specified condition becomes false.

Syntax

WHILE condition
   { statement
   | EXIT WHILE
   | CONTINUE WHILE }
   [...]
END WHILE

condition must be a boolean expression.
statement is any instruction supported by the language.

Usage

As long as the condition specified after a WHILE keyword is TRUE, all statements inside the WHILE ... END WHILE block are executed. After executing the last statement of the block, the runtime system again evaluates the condition, and if it is still TRUE, continues with the first statement in the block.

The loop stops when the condition becomes FALSE or when an EXIT WHILE is reached.

Use the CONTINUE WHILE instruction to skip the next statements and continue with the loop.

To avoid unending loops, make sure that the condition will become FALSE at some point, or that an EXIT WHILE statement will be executed.

Example

MAIN
  DEFINE cnt INTEGER
  LET cnt = 1
  WHILE cnt <= 100
    DISPLAY "Iter: " || cnt 
    LET cnt = cnt + 1
    IF int_flag THEN
      EXIT WHILE
    END IF
  END WHILE
END MAIN