Section 4.12. Infinite Loops


4.12. Infinite Loops

Perhaps surprisingly, infinite loops can often be helpful in your scripts. If you are writing a program to accept people typing in data for as long as they want, it just would not work to have the script loop 30,000 times or even 30,000,000 times. Instead, the code should loop forever, constantly accepting user input until the user ends the program by pressing Ctrl-C.

Here are the two most common types of infinite loops:

     <?php             while(1) {                     print "In loop!\n";             }     ?>

As "1" also evaluates to true, that loop will continue on forever.

     <?php             for (;;) {                     print "In loop!\n";             }     ?>

In that example, the for loop is missing the declaration, condition, and action parts, meaning that it will always loop.



PHP in a Nutshell
Ubuntu Unleashed
ISBN: 596100671
EAN: 2147483647
Year: 2003
Pages: 249

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net