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gsub! 

        # String.gsub!

(from ruby core)
---
    gsub!(pattern, replacement)   -> self or nil
    gsub!(pattern) {|match| ... } -> self or nil
    gsub!(pattern)                -> an_enumerator

---

Performs the specified substring replacement(s) on `self`; returns
`self` if any replacement occurred, `nil` otherwise.

See [Substitution Methods](#class-String-label-Substitution+Methods).

Returns an Enumerator if no `replacement` and no block given.

Related: String#sub, String#gsub, String#sub!.

This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.