如何做最大的在clojure？ [英] how to do max-by in clojure?

问题描述

如果我有一个由（defrecord Person [name age]）定义的记录序列，并且我想获得最大年龄的人的记录，

If I've got a sequence of records defined by (defrecord Person [name age]) and I want to get the record of the person with the maximum age, is there an easier way to do this than

(reduce #(if (> (:age %1) (:age %2)) %1 %2) people)

这是我想出的唯一方法到目前为止，但似乎这是一个常见的足够的情况下，必须有一些内置的库函数，使这更容易和/或更通用。

That's the only way I've figured out to do it so far, but it seems like this has to be a common enough scenario that there must be some built-in library functions that make this easier and/or more generic.

推荐答案

clojure.core / max-key 是一个合适的工作工具。

clojure.core/max-key is a suitable tool for the job.

 (apply max-key :age [{:age 12} {:age 20} {:age 30}]) ;; -> {:age 30}

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