Java Language Specification
I've been reading the Java Language Specification to improve my knowledge of the Java language. Here's a list of things I've learned:
$ identifier
The $ character can be part of a Java identifier. "for historical reasons, the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $ character should be used only in mechanically generated source code or, rarely, to access preexisting names on legacy systems."
This means I can make my Java programs look like Perl. <geshi lang="java5"> int $$ = 123; String $0 = "app"; void $(){if($$!=0)System.out.println($0);} </geshi>