WHILE...WEND
============

Function
--------

**WHILE...WEND** executes a set of statements if a condition is true.

Syntax
------

| WHILE numeric expression
| .
| .
| .
| statements
| .
| .
| .
| WEND

'numeric expression' is evaluated true or false; if the expression is
true the statements following are executed. If false, the statement
after WEND is executed. The loops may be nested; each WEND associated
with the most recent WHILE.

Examples
--------

::

    10 FOR Q=1 TO 10
    20 B(Q)=Q
    30 NEXT
   110 WHILE A< 11
   120 FOR I = 1 TO 10
   130 PRINT B(I);
   140 NEXT
   150 PRINT A:A = A+1
   160 WEND

The matrix B is printed as long as the A parameter is less than 11.

Remarks
-------

Each time WEND is encountered the expression is reevaluated. The same
precautions should be exercised in jumping out of this loop as with
:doc:`for`....\ :doc:`next` loops.

.. Warning::

   WHILE cannot be used with a string expression. The statements WHILE
   and WEND must be on separate lines and no other statements must be on
   those lines.