How do I check if a string has at least one number in it using Ruby?

user_147586 0
Viewed 24778

I need to check to see if a string contains at least one number in it using Ruby (and I assume some sort of regex?).

How would I do that?

numbers ruby regex string
5 Answers

You can use the String class's =~ method with the regex /\d/ as the argument.

Here's an example:

s = 'abc123'

if s =~ /\d/         # Calling String's =~ method.
  puts "The String #{s} has a number in it."
else
  puts "The String #{s} does not have a number in it."
end
user_425950

Alternatively, without using a regex:

def has_digits?(str)
  str.count("0-9") > 0
end
user_75520 
if /\d/.match( theStringImChecking ) then
   #yep, there's a number in the string
end
JacobM_12370

Rather than use something like "s =~ /\d/", I go for the shorter s[/\d/] which returns nil for a miss (AKA false in a conditional test) or the index of the hit (AKA true in a conditional test). If you need the actual value use s[/(\d)/, 1]

It should all work out the same and is largely a programmer's choice.

user_1284210
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