How can a JavaScript script know what version of the JavaScript language the browser supports?
Here’s a cruddy kludge that has been recommended as
a way to determine this.
It uses the language attribute of the HTML script
tag. However, many browsers just ignore that attribute.
So far it doesn’t look good:
| Browser | Platform | JavaScript Version |
|---|---|---|
| MSIE 6 | Windows | ignores |
| MSIE 5 | Mac and Windows | ignores |
| MSIE 4.01 | Mac | 1.2 |
| Firefox 3 | Linux | ignores |
| NS 6 | Mac, Linux, and Windows | 1.5 |
| NS 4.x | Mac, Linux, and Windows | ignores |
| NS 3.04 | Mac | 1.1 |
| NS 2.0 | Mac | ignores |
| Opera 9 | Linux | ignores |
| Opera 5, 6 | Mac, Linux, and Windows | 1.4 |
| iCab 2.5.2 | Mac | ignores |
| Konqueror | Linux | ignores |
| HotJava 3.0 | Java | 1.4 |
| Ice Browser 5.0.6 | Java | 1.4 |
JScript supports a nice feature called “conditional compilation” and has a means of retrieving the version of JScript that's running.