WHILE

 The WHILE statement is a loop that executes a statement while  a
 specified condition is true.


 Syntax:

    WHILE expression DO
       statement


 The 'expression' is any Boolean expression.

 The 'statement' is any VSI Pascal statement.

 VSI Pascal checks the value of  the  Boolean  expression  before
 executing the loop body for the first time; if the expression is
 FALSE, the loop body is not executed.  If the initial  value  is
 TRUE,  loop  iterations  continue  until the condition is FALSE.
 When specifying more than one statement as the loop  body  to  a
 WHILE  statement,  enclose the statements with the BEGIN and END
 reserved words, since the syntax calls for a single statement to
 follow  the  DO  reserved  word.   If  you do not use a compound
 statement for the loop  body,  VSI  Pascal  executes  the  first
 statement following the DO reserved word as the loop body.

Additional information available:

Examples