Ruby Enumerable.each_entry用法及代码示例

each_entry(*args) {|element| ... } → self

each_entry(*args) → enumerator

使用每个元素调用给定块，将多个值从 yield 转换为数组；返回 self ：

a = []
(1..4).each_entry {|element| a.push(element) } # => 1..4
a # => [1, 2, 3, 4]

a = []
h = {foo: 0, bar: 1, baz:2}
h.each_entry {|element| a.push(element) }
# => {:foo=>0, :bar=>1, :baz=>2}
a # => [[:foo, 0], [:bar, 1], [:baz, 2]]

class Foo
  include Enumerable
  def each
    yield 1
    yield 1, 2
    yield
  end
end
Foo.new.each_entry {|yielded| p yielded }

输出：

1
[1, 2]
nil

如果没有给出块，则返回 Enumerator 。