Ruby range.reduce与哈希累加器

def heights
  (60..68).reduce({}) { |h,i| h.merge!( { %(#{i/12}'#{i%12}") => i } ) }
end

它返回高度的哈希值

{
  "5'0"" => 60,"5'1"" => 61,"5'2"" => 62,"5'3"" => 63,"5'4"" => 64,"5'5"" => 65,"5'6"" => 66,"5'7"" => 67,"5'8"" => 68
}

这就是我想要的.但是,我不喜欢使用合并！方法.我更倾向于使用hash [key] = value语法进行赋值：

def heights
  (60..68).reduce({}) { |h,i| h[%(#{i/12}'#{i%12}")] = i }
end

但是这段代码会抛出错误.我知道使用reduce,在你的管道中你可以命名你的累加器和元素.

我也明白这一点

sum = 0
(1..5).each { |i| sum += i }

相当于

(1..5).reduce(0) { |sum,i| sum + i }

那么为什么不这样呢

hash = {}
(1..5).each { |i| hash[i.to_s] = i }

工作相同

(1..5).reduce({}) { |hash,i| hash["#{i}"] = i }