An efficient JavaScript compression tool download collection_javascript skills

Comparison of compression rates with other compression tools:
1. JavaScript Compressor(http://dean.edwards.name/packer/ )
With his own compression tool code as an example (v2. 02) The size after packer compression is 7,428 bytes (comments removed).
And our compression tool can compress to 7,256 bytes
7256 / 7428 = 0.9768443726440496
2. Dojo ShrinkSafe (rough stuff, inefficient and dangerous, it is recommended that original users replace it quickly)
Take his own framework source code as an example (v0.4.1):
His own compression size is 149,518 bytes, and we can reduce it to 81,261 bytes after compression
81261 / 149518 = 0.5434864029748927

Security instructions:
1.JavaScript Compressor TBCompressor(YUI Compressor) Recommended
Text-based compression, I have not looked at it carefully Logic, but the possibility of problems with this kind of compression is very low. Our compression tool also uses its compression algorithm. In the tests of JSI 1.1 a8 and
its integrated third-party class library, no abnormalities were found. Moreover, the well-known framework JQuery is used, so I believe there will be no problems.

2.Dojo ShrinkSafe is dangerous! ! ! ! !
Use shorter names to replace long local variable names. This is an extremely unsafe compression tool. For example:

java code


function(){
var withObject = {variable1:1}
var variable1 = 2;
with(withObject){
alert(variable1);
}
}

will Compressed into
java code


function(){
var _1={variable1:1};
var _2=2;
with(_1){
alert(_2);
}
}

This is obviously wrong. This garbage does not pay attention to some special syntax and dynamics of javascript.
No processing is done on the eval function, catch operation, and with statement.
In comparison, JSA is the safest and most effective compression tool that I currently know.
JSA not only provides code compression function, but also can do formatting and script analysis.

The script analysis function can be used to view script information and find potential problems in the script.
For example, check which functions and variables are declared in the script.
Those external variables are used. etc. . .

JSA’s compression process is divided into two steps. The first step is syntax compression, which is similar to Dojo ShrinkSafe, but safer and more effective than it.

The second step is text compression. Currently, the compression algorithm of
JavaScript Compressor is used.
(http://dean.edwards.name/packer/ )

These can be set in the settings window.

By default, syntax compression is used first. When the file is larger than 1000k and text compression can still be compressed to 90% of the original size, text compression is used on the original basis.

Download address:
http://sourceforge.net/project/showfiles.php?group_id=175776
or
http://forum .xidea.orgFile List