1.
sort → new_ary
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sort { |a, b| block } → new_ary
Returns a new array created by sorting self.
Comparisons for the sort will be done using the <=> operator or using an optional code block.
The block must implement a comparison between a and b, and return -1, when a follows b, 0 when a and b are equivalent, or +1 if b follows a.
See also Enumerable#sort_by.
a = [ "d", "a", "e", "c", "b" ] a.sort #=> ["a", "b", "c", "d", "e"] a.sort { |x,y| y <=> x } #=> ["e", "d", "c", "b", "a"]
a.sort { |x,y| x <=> Y } #=> ["a", "b", "c", "d", "e"]
2.
sort! → ary
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sort! { |a, b| block } → ary
Sorts self in place.
Comparisons for the sort will be done using the <=> operator or using an optional code block.
The block must implement a comparison between a and b, and return -1, when a follows b, 0 when a and b are equivalent, or +1 if b follows a.
See also Enumerable#sort_by.
a = [ "d", "a", "e", "c", "b" ] a.sort! #=> ["a", "b", "c", "d", "e"] a.sort! { |x,y| y <=> x } #=> ["e", "d", "c", "b", "a"]
參考鏈接：http://www.ruby-doc.org/core-2.0/Array.html#method-i-sort
3.sort和sort！的區別：
sort和sort!函數，默認都使用 <=>比較，他們的區別在於：
sort! 可能會改變原先的數組，所以加個感嘆號提醒
sort 返回的是新數組，沒對原先的數組進行修改
在ruby的SDK里，能看到很多加了感嘆號的函數，都意味着對函數操作的對象進行了狀態更改。