Hiding JS code from old browsers

JavaScript FAQ | Basic Syntax & General Questions  

Question: How do I hide JS code from old browsers that do not support JavaScript?

Answer: This question has become far less relevant now that virtually all browsers support JavaScript. Nevertheless, to prevent old browsers from displaying your JS code, you can do the following:

  1. Immediately after the opening <script> tag, put a one-line HTML-style comment without the closing characters, so that the first two lines of your script would look like this:
    <script type="text/javascript" language="JavaScript">
  2. At the end of your script, put the following two lines:
Thus, your HTML file will contain the following fragment:
<script language="JavaScript">
Here you put your JS code.
Old browsers will treat it
as an HTML comment.

Old browsers will treat your JS code as one long HTML comment. On the other hand, new JavaScript-aware browsers will normally interpret JS code between the tags <script> and </script> (the first and last lines of your JS code will be treated by the JavaScript interpreter as one-line comments).

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