从哈希数组导轨选择最大值 [英] rails select maximum value from array of hash

问题描述

我有这样的散列的数组，我想利用这一最大值

i have a array of hashes like this and i want to take the maximum value of that

data = [{name: "abc", value: "10.0"}, {name: "def", value: "15.0"}, {name: "ghi", value: "20.0"}, {name: "jkl", value: "50.0"}, {name: "mno", value: "30.0"}]

我要选择哈希数组的最大值，输出我要的是像数据：50.0

i want to select the maximum value of array of hashes, output i want is like data: "50.0"

我怎么可能做到这一点，我已经尝试这一点，但它似乎是不工作，只是给我一个错误

how possible i do that, i've try this but it is seem doesnt work and just give me an error

data.select {|x| x.max['value'] }

任何帮助将是非常美联社preciated

any help will be very appreciated

推荐答案

有大量的在Ruby中这样做的方法。这里有两个。你可以传递给阵列＃最大块如下：

There are lots of ways of doing this in Ruby. Here are two. You could pass a block to Array#max as follows:

  > data.max { |a, b| a[:value] <=> b[:value] }[:value]
   => "50.0"

或者你可以使用阵列＃地图来撕开：值输入了哈希：

  > data.map { |d| d[:value] }.max
   => "50.0"

请注意，您可能需要使用 #to_f 或浮动（...）来避免做与字符串字符串比较，这取决于你的使用情况是什么。

Note that you might want to use #to_f or Float(...) to avoid doing String-String comparisons, depending on what your use case is.

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