Check if string starts with number-CodePudding

How can I check if my string starts with a number?

I'm trying to make this work by using the starts_with ruby method with no luck:

<% if line.start_with?("ANY NUMBER") %>

Thanks!

CodePudding user response：

Just do this :

def starts_with_number?(str)
  str.start_with?(*'0'..'9')
end

puts starts_with_number?("123abc") # true

puts starts_with_number?("abc123") # false

puts starts_with_number?("1.23") # true

puts starts_with_number?("-123") # true

CodePudding user response：

In Regular Expressions, \A means start of string, and \d means any digit. So this could work for you:

if line.match?(/\A\d/)