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End of Life Ruby 3.0 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

class · Ruby 3.0

KeyError

< IndexError 2 instance methods 1 class methods

Raised when the specified key is not found. It is a subclass of IndexError.

Example

h = {"foo" => :bar}
h.fetch("foo") #=> :bar
h.fetch("baz") #=> KeyError: key not found: "baz"

Class methods 1