Home  >  Article  >  Web Front-end  >  Is Using `navigator.appName` and `navigator.appVersion` Reliable for Detecting Older IE Versions?

Is Using `navigator.appName` and `navigator.appVersion` Reliable for Detecting Older IE Versions?

Mary-Kate Olsen
Mary-Kate OlsenOriginal
2024-11-06 14:54:02829browse

Is Using `navigator.appName` and `navigator.appVersion` Reliable for Detecting Older IE Versions?

Detect IE Version (Prior to v9) in JavaScript

Detection Criteria and Proposed Code

To determine if a user is accessing a website using a version of Internet Explorer prior to v9, the proposed code leverages the navigator.appName and navigator.appVersion properties.

if (navigator.appName.indexOf("Internet Explorer") != -1) {
    // User is using IE
    // Check for IE version < 9
}

Will This Code Do the Trick?

Despite addressing the concerns raised about user agent string spoofing and feature support detection, the proposed code has several limitations:

  • Conditional statements: While conditional statements are useful for targeting different IE versions, they are only supported in IE5-9, so this approach is obsolete in modern browsers.
  • Precision (IE 1 and IE 10 ): The code fails to detect IE 1 and IE versions greater than or equal to 10.
  • Completeness: The code only checks for IE versions less than 9, ignoring potential edge cases.

A Preferred Alternative

To overcome these limitations, a more comprehensive approach involves using CSS class-based detection:

  1. Define CSS classes that represent different IE versions, e.g.:
html.lt-ie9 { ... }
html.lt-ie8 { ... }
html.lt-ie7 { ... }
  1. Apply these classes to the element based on the detected IE version:
    <!--[if lt IE 7]> <html class="lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
    <!--[if IE 7]>    <html class="lt-ie9 lt-ie8"> <![endif]-->
    <!--[if IE 8]>    <html class="lt-ie9"> <![endif]-->
    <!--[if gt IE 8]><!--> <html> <!--<![endif]-->
    1. Use CSS to specify styles specific to the detected IE version, or implement JavaScript logic based on the assigned class:
    if ($('html').is('.lt-ie7, .lt-ie8, .lt-ie9')) {
        // IE version < 9
    } else {
        // Other browsers
    }

    This method provides more flexibility, compatibility, and control for handling different browser versions.

    The above is the detailed content of Is Using `navigator.appName` and `navigator.appVersion` Reliable for Detecting Older IE Versions?. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn