How to hide javascript code from old browsers that dont run it?

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Use the below specified style of comments

<script language=javascript>

<!–javascript code goes here–>

Or

Use the <NOSCRIPT>some html code </NOSCRIPT> tags and code the display html statements between these and this will appear on the page if the browser does not support javascript.

To hide JavaScript code from old browsers that don’t run it, you can use conditional comments or feature detection techniques. Here’s how you can approach it:

  1. Feature Detection:
    • Use feature detection to check if a browser supports a certain JavaScript feature before executing the code. Libraries like Modernizr can help with feature detection.
    • Example:
      javascript
      if (window.localStorage) {
      // Your modern code here
      } else {
      // Fallback code for older browsers
      }
  2. Conditional Comments (for Internet Explorer):
    • Conditional comments are specific to Internet Explorer. You can use them to include or exclude JavaScript based on the version of IE.
    • Example:
      html
      <!--[if lt IE 9]>
      <script src="fallback.js"></script>
      <![endif]-->
  3. Progressive Enhancement:
    • Structure your code in a way that essential functionality works even if JavaScript is disabled or not supported.
    • Use JavaScript to enhance the user experience rather than relying on it for core functionality.
  4. Graceful Degradation:
    • Design your application so that it works in older browsers without the latest JavaScript features but provides an enhanced experience for modern browsers.
  5. Polyfills:
    • Use polyfills to provide modern JavaScript features in older browsers. These are scripts that emulate the behavior of newer features.
    • Example:
      html
      <script src="polyfill.js"></script>
      <script src="modern-script.js"></script>
  6. User-Agent Detection (not recommended):
    • You can detect the user-agent string of the browser, but this approach is generally not recommended due to its unreliability and potential for misuse.

Overall, using feature detection along with progressive enhancement and graceful degradation strategies is the most recommended approach for handling JavaScript in various browser environments.