JavaScript Versions
Question: What JavaScript versions are there?
Answer:
JavaScript
is one of the youngest programming languages.
It was first implemented by Netscape Communications in 1995.
The first browser to support JavaScript was Netscape Navigator 2.0 beta version.
By 1999 the two major browsers,
Netscape Navigator and Microsoft Internet Explorer,
supported the following client-side versions of JavaScript:
| Browser | Year | JavaScript Version |
| Netscape Navigator 2.0 | 1995 | JavaScript 1.0 |
| Microsoft Internet Explorer 3.0 | 1996 | JavaScript 1.0 (JScript 1.0) |
| Netscape Navigator 3.0 | 1996 | JavaScript 1.1 |
| Netscape Navigator 4.0 | 1997 | JavaScript 1.2 |
| Microsoft Internet Explorer 4.0 | 1997 | JavaScript 1.2 (JScript 3.0) |
| Netscape Navigator 4.5 | 1998 | JavaScript 1.3 |
| Microsoft Internet Explorer 5.0 | 1999 | JavaScript 1.3 (JScript 5.0) |
Unfortunately, Netscape and Microsoft implementations of JavaScript are different,
even for the same JavaScript version number.
For example, JavaScript 1.0 in Internet Explorer 3 differs from JavaScript 1.0 in
Netscape Navigator 2; similarly, JavaScript 1.2 in Internet Explorer 4 is not the same as
JavaScript 1.2 in Netscape Navigator 4.
In addition to these JavaScript versions,
third parties can also create their own JavaScript implementations,
or license the JavaScript technology from either Microsoft or Netscape.
For example, the Opera
browsers now support JavaScript.
What does that mean for cross-platform coding?
Essentially, you have to use either of the following techniques:
- use only a subset of the JavaScript language
that is supported by all target browsers and/or
- write different code segments for different browsers,
and detect the actual browser at run time.
Be sure to test your scripts on
all target platforms.
JavaScripter.net.
Copyright
© 1999-2006, Alexei Kourbatov
