如何在 Ruby 中创建自定义排序方法 [英] How to create a custom sort method in Ruby

问题描述

我想指定一个自定义块方法，通过评估两个属性来对对象数组进行排序.但是，经过多次搜索，我没有找到任何没有 <=> 运算符的示例.

I want to specify a custom block method to sort an object array by evaluating two properties. However, after many searches, I didn't find to any example without the <=> operator.

我想将 a 与 b 进行比较:

I want to compare a to b:

if a.x less than b.x return -1
if a.x greater than b.x return 1
if a.x equals b.x, then compare by another property , like a.y vs b.y

这是我的代码，但它不起作用:

This is my code and it doesn't work:

ar.sort! do |a,b|
   if a.x < b.y return -1
   elseif a.x > b.x return 1
   else return a.y <=> b.y
end

这个块在一个函数内 return 正在退出函数并返回 -1.

This block is within a function return is exiting the function and returning -1.

推荐答案

最佳答案由@AJcodez提供如下:

The best answer is provided by @AJcodez below:

points.sort_by{ |p| [p.x, p.y] }

我最初提供的正确"答案虽然在技术上有效，但不是我建议编写的代码.我记得我的回答是为了适应问题对 if/else 的使用，而不是停下来思考或研究 Ruby 是否有一种更具表现力、更简洁的方式，当然，确实如此.

The "correct" answer I originally provided, while it technically works, is not code I would recommend writing. I recall composing my response to fit the question's use of if/else rather than stopping to think or research whether Ruby had a more expressive, succinct way, which, of course, it does.

使用 case 语句:

ar.sort do |a, b|
  case
  when a.x < b.x
    -1
  when a.x > b.x
    1
  else
    a.y <=> b.y
  end
end 

与三元:

ar.sort { |a,b| a.x < b.x ? -1 : (a.x > b.x ? 1 : (a.y <=> b.y)) }

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