ruby 如何检查变量是数字还是字符串？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8616360/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to check if a variable is a number or a string?
提问by Leem.fin
How to check if a variable is a number or a string in Ruby?
如何在Ruby中检查变量是数字还是字符串？
回答by Michael Kohl
There are several ways:
有几种方式：
>> 1.class #=> Fixnum
>> "foo".class #=> String
>> 1.is_a? Numeric #=> true
>> "foo".is_a? String #=> true
回答by installero
class Object
def is_number?
to_f.to_s == to_s || to_i.to_s == to_s
end
end
> 15.is_number?
=> true
> 15.0.is_number?
=> true
> '15'.is_number?
=> true
> '15.0'.is_number?
=> true
> 'String'.is_number?
=> false
回答by Christoph Geschwind
var.is_a? String
var.is_a? Numeric
回答by Frank Koehl
The finishing_movesgemincludes a String#numeric?method to accomplish this very task. The approach is the same as installero's answer, just packaged up.
该finishing_moves宝石包括String#numeric?完成这项任务非常方法。方法和installero的回答一样，只是打包好了。
"1.2".numeric?
#=> true
"1.2e34".numeric?
#=> true
"1.2.3".numeric?
#=> false
"a".numeric?
#=> false
回答by BSalunke
Print its class, it will show you which type of variable is (e.g. String or Number).
打印它的类，它会告诉你是哪种类型的变量（例如字符串或数字）。
e.g.:
例如：
puts varName.class
回答by markhorrocks
class Object
def numeric?
Float(self) != nil rescue false
end
end
回答by Liker777
if chr.to_i != 0
puts "It is number, yep"
end
