Method: Array#only

Defined in:
lib/core/facets/array/only.rb

#only ⇒ Object

Returns the only element in the array. Raises an IndexError if the array’s size is not 1.

[5].only      # => 5

expect IndexError do
  [1,2,3].only
end

expect IndexError do
  [].only
end

CREDIT: Gavin Sinclair, Noah Gibbs



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# File 'lib/core/facets/array/only.rb', line 18

def only
  unless size == 1
    raise IndexError, "Array#only called on non-single-element array"
  end
  first
end