CODEWITHSUNDEEP
rubyregexstringnumbers
Shpigford
Shpigford

Reputation: 25328

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

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?

Upvotes: 19

Views: 27326

Answers (5)

Shreyas
Shreyas

Reputation: 1534

!s[/\d/].nil?

Can be a standalone function - 

def has_digits?(s)
  return !s[/\d/].nil?
end

or ... adding it to the String class makes it even more convenient - 

class String
  def has_digits?
    return !self[/\d/].nil?
  end
end

Upvotes: 4

the Tin Man
the Tin Man

Reputation: 160551

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.

Upvotes: 3

glenn jackman
glenn jackman

Reputation: 246744

Alternatively, without using a regex:

def has_digits?(str)
  str.count("0-9") > 0
end

Upvotes: 13

Ethan
Ethan

Reputation: 60099

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

Upvotes: 41

Jacob Mattison
Jacob Mattison

Reputation: 51052

if /\d/.match( theStringImChecking ) then
   #yep, there's a number in the string
end

Upvotes: 5

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