Regex that accepts floating point numbers and minus (-) sign

Question

I want a regular expression that will accept only floating point numbers from 0 to 9 and minus sign.

Please help.

Answer 1

Try ^[-+]?[0-9]*[.,]?[0-9]+$.

This regular expression will match an optional sign, that is either followed by zero or more digits followed by a dot and one or more digits (a floating point number with optional integer part), or followed by one or more digits (an integer).

Source: http://www.regular-expressions.info/floatingpoint.html - altered to work with commas as decimal separator

Answer 2

^[-+]?[0-9]*\.?[0-9]+$

• ^ - start of string
• [-+]? - 0 or 1 sign indicator
• [0-9]* - 0 or more integers
• \. - the character . (. is used in regex to mean "any character")
• [0-9]+ - 1 or more integers
• $ - the end of the string

If you are instead using the comma as a decimal seperator, use , instead of \.

If you are using both/either, you can use [.,]