Advanced javascript

We are familiar with the

#ifndef __FTP__

#define __FTP__

.......

#else

#endif

Known in c/c++/c#

It turns out to me that internet explorer supports this feature too. 

The keywords are:

@cc_on,@set, @if, @else, @elif and @end

Example:

@cc_on

@set @filename = 'test'

@if @filename == 'test'

@else

@end

You probably ask what is this '@" sign before the instruction, well, that's part of the Microsoft extensions to javascript.

There are some more to try:

@_win32,@_win16, @_x86 ... these are somewhat deprecated.

@_jscript_version

The Dictionary object:

var dict = new ActiveXObject("Scripting.Dictionary");

dict.Add('key','value');