var
keyword:!
at the end of a method changes the variable in-place (almost like in Ruby)::=
(also available as \\=
), assigns a value to a variable if the current value of the variable is nil
:\\
can be used for checking if a variable is defined or not:ARGV
is an Array that contains the program's command-line arguments, that were not given to Sidef.ENV
is an Hash copy of environment variables and their values when the program was started.ARGF
is a FileHandle object used to read lines from argument-files or from STDIN
when no argument has been specified.DATA
is a FileHandle object that points to the data stored after the __END__
or __DATA__
tokens._
) is declared at compile-time in each block-object in the program. You may not see its real name very often, because it has been overtaken by the elegant prefix dot (.) operator:.sqrt
really means _.sqrt
, and .log.say
means _.log.say
.