我想简单地检查一下,从形式文本领域返回的价值是多少,即12.5或12.75。 是否有一个简单的检查方法,特别是如果价值被作为<条码>第
仅仅看一看,它就很奇怪,不值得思考:
v =~ /A[-+]?[0-9]*.?[0-9]+/
(根据Justin的评论确定)
你们可以使用
12.is_a? Numeric
(Numeric ,将适用于 in和浮体。)
如果它作为可能包含有效数目的代表的扼杀手段,你可以使用。
class String
def valid_float?
true if Float self rescue false
end
end
然后,12 .valid_float? 如果你能够将舱面转换为有效浮标(例如to_f),将恢复有效。
我通常在几天前就使用Integer和Float。
1.9.2p320 :001 > foo = "343"
=> "343"
1.9.2p320 :003 > goo = "fg5"
=> "fg5"
1.9.2p320 :002 > Integer(foo) rescue nil
=> 343
1.9.2p320 :004 > Integer(goo) rescue nil
=> nil
1.9.2p320 :005 > Float(foo) rescue nil
=> 343.0
1.9.2p320 :006 > Float(goo) rescue nil
=> nil
改道:
num = 12
num == num.to_i.to_s
#=> true
num = 3re
num == num.to_i.to_s
#=> false
我建议这样做。
def is_a_number?(str)
!!(Float(str) rescue false)
end
> is_a_number?(1)
=> true
> is_a_number?(1.1)
=> true
> is_a_number?( 1 )
=> true
> is_a_number?( 1.1 )
=> true
> is_a_number?( a )
=> false
> is_a_number?(nil)
=> false
irb(main):005:0> 1.1.is_a? Numeric
=> true
irb(main):006:0> 1.is_a? Numeric
=> true
irb(main):007:0> asd .is_a? Numeric
=> false
回答如下:Kernel#Float 。
但这一变式用在<代码>除外:假 钥匙和双管齐下,以回包。
class String
def number?
!!Float(self, exception: false)
end
end
例如:
irb(main):015:0> 12.5.to_s.match?(/^-?d+(.d+)?$/)
=> true
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