我有下面的数组
cities = ["Kathmandu", "Pokhara", "", "Dharan", "Butwal"]
我想从数组中删除空白元素，并希望得到以下结果:
cities = ["Kathmandu", "Pokhara", "Dharan", "Butwal"]
有没有像compact这样不需要循环的方法?
当前回答
这里还有一种方法可以实现这一点
我们可以使用presence和select
cities = ["Kathmandu", "Pokhara", "", "Dharan", nil, "Butwal"]
cities.select(&:presence)
["Kathmandu", "Pokhara", "Dharan", "Butwal"]
其他回答
有很多方法可以做到这一点，其中之一是拒绝
noEmptyCities = cities.reject { |c| c.empty? }
你也可以用reject!，这将改变城市的位置。如果拒绝某项，它将返回cities作为返回值，如果没有拒绝，则返回nil。如果你不小心，这可能是一个陷阱(感谢ninja08在评论中指出这一点)。
在我的项目中，我使用delete:
cities.delete("")
如果你的数组中有混合类型，下面是一个解决方案:
[nil,"some string here","",4,3,2]
解决方案:
[nil,"some string here","",4,3,2].compact.reject{|r| r.empty? if r.class == String}
输出:
=> ["some string here", 4, 3, 2]
纯Ruby:
values = [1,2,3, " ", "", "", nil] - ["", " ", nil]
puts values # [1,2,3]
最明确的
cities.delete_if(&:blank?)
这将删除nil值和空字符串("")值。
例如:
cities = ["Kathmandu", "Pokhara", "", "Dharan", "Butwal", nil]
cities.delete_if(&:blank?)
# => ["Kathmandu", "Pokhara", "Dharan", "Butwal"]
