In a rails application, I have an array of hashes which I can sort easily with just
在rails应用程序中，我有一个哈希数组，我可以轻松地排序
array_of_hashes.sort_by { |hash| hash[:key_to_sort] }
But what if not every array member has a key :key_to_sort? Then the sort will fail "comparison of String with nil failed". Is there a way to allow the sort to continue? Or is there another way to do this?
但是，如果不是每个数组成员都有一个键：key_to_sort？然后排序将失败“String与nil的比较失败”。有没有办法让排序继续下去？或者还有另一种方法吗？
1 个解决方案
#1
12
It depends what you want to do when a hash doesn't have sorting key. I can imagine two scenarios:
这取决于当哈希没有排序键时你想要做什么。我可以想象两种情况：
1) exclude the hash from sorting
1）从排序中排除哈希
arr.delete_if { |h| h[:key_to_sort].nil? }.sort_by { |h| h[:key_to_sort] }
2) place the hash at the beginning/end of the array:
2）将哈希放在数组的开头/结尾：
arr.sort_by { |h| h[:key_to_sort] || REALLY_SMALL_OR_LARGE_VALUE }
#1
12
It depends what you want to do when a hash doesn't have sorting key. I can imagine two scenarios:
这取决于当哈希没有排序键时你想要做什么。我可以想象两种情况：
1) exclude the hash from sorting
1）从排序中排除哈希
arr.delete_if { |h| h[:key_to_sort].nil? }.sort_by { |h| h[:key_to_sort] }
2) place the hash at the beginning/end of the array:
2）将哈希放在数组的开头/结尾：
arr.sort_by { |h| h[:key_to_sort] || REALLY_SMALL_OR_LARGE_VALUE }