ruby--数组常用方法

一、max_by,min_by根据条件取出数组中的最大值最小值

1 str = "this is a string"
2 arr = str.split(" ")
3 p arr.min_by { |e| e.length } #"a"
4 p arr.max_by { |e| e.length } # "string"

二、find 找出匹配的第一个元素

1 str = "this is a string"
2 arr = str.split(" ")
3 p arr.find { |e| e.length == 1 } # "a"

三、select 找出匹配的所有元素

1 str = "this is a string"
2 arr = str.split(" ")
3 p arr.select { |e| e.length > 1 } # ["this", "is", "string"]

 四、排序

arr = [11, 23, 43, 32]
#排序
arr.sort # [11,23,32,43]
arr.sort! # a = [11,23,32,43]

#反转
arr.reverse #[32,43,23,11]
#乱序
arr.shuffle #

 五、自定义排序

arr="this is a string".split(" ") 
#按元素长度降序
arr.sort! { |a,b| b.length <=> a.length }     

#按元素长度升序

arr.sort! { |a,b| a.length <=> b.length }