Public Instance Methods| ruby-doc.org
A Proc object is an encapsulation of a block of code, which can be stored in a local variable, passed to a method or another Proc, and can be called. Proc is an essential concept in Ruby and a core of its functional programming features.| ruby-doc.org
A String object has an arbitrary sequence of bytes, typically representing text or binary data. A String object may be created using String::new or as literals.| ruby-doc.org