Regex for numbers only

Question

I haven\'t used regular expressions at all, so I\'m having difficulty troubleshooting. I want the regex to match only when the contained string is all numbers; but with the

Answer 1

Sorry for ugly formatting. For any number of digits:

[0-9]*

For one or more digit:

[0-9]+

Answer 2

Another way: If you like to match international numbers such as Persian or Arabic, so you can use following expression:

Regex = new Regex(@"^[\p{N}]+$");

To match literal period character use:

Regex = new Regex(@"^[\p{N}\.]+$");

Answer 3

Your regex will match anything that contains a number, you want to use anchors to match the whole string and then match one or more numbers:

regex = new Regex("^[0-9]+$");

The ^ will anchor the beginning of the string, the $ will anchor the end of the string, and the + will match one or more of what precedes it (a number in this case).

Answer 4

Regex for integer and floating point numbers:

^[+-]?\d*\.\d+$|^[+-]?\d+(\.\d*)?$

A number can start with a period (without leading digits(s)), and a number can end with a period (without trailing digits(s)). Above regex will recognize both as correct numbers.

A . (period) itself without any digits is not a correct number. That's why we need two regex parts there (separated with a "|").

Hope this helps.

Answer 5

If you need to check if all the digits are number (0-9) or not,

^[0-9]+$

1425 TRUE

0142 TRUE

0 TRUE

1 TRUE

154a25 FALSE

1234=3254 FALSE

Answer 6

Use beginning and end anchors.

 Regex regex = new Regex(@"^\d$");

Use "^\d+$" if you need to match more than one digit.