by Perl, but in this case, the notation was made simpler: a global variable name must be preceded by a $ sign, like $variable_name, while a local variable has simply no $ sign in front of its name, like variable_name (while in perl all scalar values have a $ in front). Note that Ruby only provides built-in support for statically-scoped local variables like Perl's my, not dynamically-scoped local variables like Perl's local. There is at least one library for Ruby that provides dynamically-scoped variables. See also Global variable Non-local variable References Variable (computer science)