[英]How can I judge whether if form input value is number or not?
I'd like to proceed transaction
when params[:points]
is not a number. 当
params[:points]
不是数字时,我想进行transaction
。 I coded like this. 我这样编码。
if params[:points] !=~ /^[+-]?\d+$/
transaction
end
However, it proceeds transaction
even when I input abcdefh
into params[:points]
. 但是,即使我将
abcdefh
输入到params[:points]
,它也会继续进行transaction
。 How can I fix? 我该如何解决?
All values received from a form are Strings. 从表单接收的所有值都是字符串。 Some might look like a numeric value, but they'll remain strings until you explicitly convert them to an integer, which you can do using String's
to_i
method. 有些可能看起来像数字值,但它们将保留为字符串,直到您将其显式转换为整数为止,您可以使用String的
to_i
方法进行此操作。
You can check to see if the entire value contains digits, which is a good clue that it's truly a number using something like: 您可以使用以下方法检查整个值是否包含数字,这可以很好地表明它确实是数字:
!!params[:points][/^[+-]?\d+$/]
to return true/false if it's a string version of a number. 如果它是数字的字符串版本,则返回true / false。
'012345'[/^[+-]?\d+$/]
=> "012345"
!!'012345'[/^[+-]?\d+$/]
=> true
'+012345'[/^[+-]?\d+$/]
=> "+012345"
!!'+012345'[/^[+-]?\d+$/]
=> true
'-+012345'[/^[+-]?\d+$/]
=> nil
!!'-012345'[/^[+-]?\d+$/]
=> true
'0 foo'[/^[+-]?\d+$/]
=> nil
!!'0 foo'[/^[+-]?\d+$/]
=> false
I think you want .match
, not !=~
. 我认为您想要
.match
,而不是!=~
。
unless params[:points].match(/^[+-]?\d+$/)
#stuff
end
Alternatively, I finally figured out that the 'does not match' operator exists, it's just that it's !~
, not !=~
. 或者,我最终发现存在“不匹配”运算符,只是
!~
而不是!=~
。 So yeah, taking out that equals sign should also solve your problem. 是的,去掉等号也可以解决您的问题。
Maybe you are confused by your own logic. 也许您对自己的逻辑感到困惑。
params[:points]
is "abcdefh"
params[:points]
是"abcdefh"
params[:points] !=~ /^[+-]?\\d+$/
params[:points] !=~ /^[+-]?\\d+$/
transaction
is executed transaction
On the other hand, 另一方面,
I'd like to proceed transaction when params[:points] is not a number
我想在params [:points]不是数字时继续进行交易
That is exactly the case. 确实是这样。 Nothing is wrong.
没有错误。
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