@_
array within the lexical scope of subroutines and formats, and the
@ARGV
array at file scopes or within the lexical scopes established by the eval '', BEGIN {}
, END {}
, and INIT {}
constructs. See also unshift(), push(), and pop(). Shift()
and unshift() do the same thing to the left end of an array that pop() and push() do to the right end.