While

A related function is While(), which repeatedly tests the condition and evaluates its body script as long as the condition is true. The syntax is:

While( condition, body );

For example, here are two different programs that use a While() loop to find the least power of 2 that is greater than or equal to x (287). The result of both programs is 512.

x = 287;

// loop 1:

y = 1;

While( y < x, y *= 2 );

Show( y );

// loop 2:

k = 0;

While( 2 ^ k < x, k++ );

Show( 2 ^ k );

The scripts work like this:

x = 287;	Sets x to 287.
// loop 1
y = 1;	Sets y to 1.
While(	Begins the While() loop.
y < x,	As long as y is less than x, continues evaluating the loop.
y *= 2	Multiplies 1 by 2 and then assigns the result to y. The loop then repeats while y is less than 287.
);	Ends the loop.
Show(y);	Shows the value of y (512).
// loop 2
k = 0;	Sets k to 0.
While(	Begins the While() loop.
2 ^ k < x,	Raises 2 to the exponent power of k and continues evaluating the loop as long as the result is less than 287.
k++	Increments k to 1. The loop then repeats while 2 ^ k is less than 287.
);	Ends the loop.
Show(2 ^ k);	Shows the value of 2 ^ k (512).

As with For() loops, While() loops that always evaluate as true create an infinite loop, which never stops. To stop the script, press ESC on Windows (or COMMAND-PERIOD on Macintosh). You can also select Edit > Stop Script. On Macintosh, Edit > Stop Script is available only when the script is running.