Method: Hash#fetch

Defined in:

ext/enterprise_script_service/mruby/mrbgems/mruby-hash-ext/mrblib/hash.rb

#fetch(key, none = NONE, &block) ⇒ Object

call-seq:

   hsh.fetch(key [, default] )       -> obj
   hsh.fetch(key) {| key | block }   -> obj

Returns a value from the hash for the given key. If the key can't be
found, there are several options: With no other arguments, it will
raise an <code>KeyError</code> exception; if <i>default</i> is
given, then that will be returned; if the optional code block is
specified, then that will be run and its result returned.

   h = { "a" => 100, "b" => 200 }
   h.fetch("a")                            #=> 100
   h.fetch("z", "go fish")                 #=> "go fish"
   h.fetch("z") { |el| "go fish, #{el}"}   #=> "go fish, z"

The following example shows that an exception is raised if the key
is not found and a default value is not supplied.

   h = { "a" => 100, "b" => 200 }
   h.fetch("z")

<em>produces:</em>

   prog.rb:2:in 'fetch': key not found (KeyError)
    from prog.rb:2

# File 'ext/enterprise_script_service/mruby/mrbgems/mruby-hash-ext/mrblib/hash.rb', line 171

def fetch(key, none=NONE, &block)
  unless self.key?(key)
    if block
      block.call(key)
    elsif none != NONE
      none
    else
      raise KeyError, "Key not found: #{key.inspect}"
    end
  else
    self[key]
  end
end