Ruby Pocket Reference

Pseudovariables

Table 4 shows Ruby’s pseudovariables. A pseudovariable is an object that looks like a variable, acts like a constant, and can’t be assigned a value. These are also listed in Table 1.

Table 4. Pseudovariables in Ruby

Pseudovariable	Description
false	Logical or Boolean false; instance of FalseClass.
nil	Empty, uninitialized, or invalid; always false, but not the same as zero; object of NilClass.
self	Current object (receiver invoked by a method).
true	Logical or Boolean true; instance of TrueClass.
_ _FILE_ _	Name of current source file.
_ _LINE_ _	Number of current line in the current source file.