此答案是 James Kyburz对类似问题的回答的副本
红宝石中没有这个,最接近的是自我。
这里有一些例子可以帮助你在你的路上
#example 1 not self needed numbers is the array
numbers = [1, 2, 3]
numbers.reduce(:+).to_f / numbers.size
# example 2 using tap which gives access to self and returns self
# hence why total variable is needed
total = 0
[1, 2, 3].tap {|a| total = a.reduce(:+).to_f / a.size }
# instance_eval hack which accesses self, and the block after do is an expression
# can return the average without an extra variable
[1, 2, 3].instance_eval { self.reduce(:+).to_f / self.size } # => 2.0
到目前为止,我更喜欢示例 1