JavaScript Limitations

Question: What can't JavaScript programs do?

Answer: JavaScript code cannot do any of the following:

If you do need to access files or perform other "privileged" operations, you can use JavaScript in combination with a Java applet. Signed Java applets are allowed to do "privileged" things, and your JavaScript programs can exchange information with applets. However, you have to bear in mind the biggest JavaScript/Java limitation: the user can always disable Java or JavaScript or both!