Detect version of JavaScript

Question

How can I detect what version of JavaScript the browser supports (if any)? I want to check for ECMAScript 3 versus ECMAScript 5 versus ECMAScript 6.

Note: I want to avoid the deprecated language tag.

Answer 1

Here is a good reference for you: http://www.docsteve.com/DocSteve/Samples/JS/js_version.html

Basically, use the deprecated language attribute of the script tag

<script language="javascript">var js_version="1.0"</script> <script language="javascript1.1">var js_version="1.1"</script> <script language="javascript1.2">var js_version="1.2"</script> <script language="javascript1.3">var js_version="1.3"</script> <script language="javascript1.4">var js_version="1.4"</script> <script language="javascript1.5">var js_version="1.5"</script> <script language="javascript1.6">var js_version="1.6"</script> 

Answer 2

The solution proposed to http://www.docsteve.com/DocSteve/Samples/JS/js_version.html as simple JavaScript function (using "createElement" construction):

<script type="text/javascript"> function get_js_version () {     this.jsv = {             versions: [                 "1.1", "1.2", "1.3", "1.4", "1.5", "1.6", "1.7", "1.8", "1.9", "2.0"             ],             version: ""         };      var d = document;      for (i = 0; i < jsv.versions.length; i++) {         var g = d.createElement('script'),             s = d.getElementsByTagName('script')[0];              g.setAttribute("language", "JavaScript" + jsv.versions[i]);             g.text = "this.jsv.version='" + jsv.versions[i] + "';";             s.parentNode.insertBefore(g, s);     }      return jsv.version; }  document.write('JavaScript Version: ' + get_js_version()); </script>