How to check if a variable is a number or a string?

Question

How to check if a variable is a number or a string in Ruby?

Answer 1

There are several ways:

>> 1.class #=> Fixnum >> "foo".class #=> String >> 1.is_a? Numeric #=> true >> "foo".is_a? String #=> true 

Answer 2

 class Object def is_number? self.to_f.to_s == self.to_s || self.to_i.to_s == self.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 

Answer 3

 var.is_a? String var.is_a? Numeric 

Answer 4

finishing_moves stone includes String#numeric? a method to accomplish this very task. The approach is the same as the installero answer, just packaged.

 "1.2".numeric? #=> true "1.2e34".numeric? #=> true "1.2.3".numeric? #=> false "a".numeric? #=> false 

Answer 5

Print out your class, it will show you what type of variable (e.g. String or Number).

eg:.

 puts varName.class 

Answer 6

 class Object def numeric? Float(self) != nil rescue false end end 

Answer 7

 if chr.to_i != 0 puts "It is number, yep" end