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

If you need to tolerate decimal point and thousand marker

var regex = new Regex(@"^-?[0-9][0-9,\.]+$");

You will need a "-", if the number can go negative.

Answer 2

 console.log(/^(0|[1-9][0-9]*)$/.test(3000)) // true

Answer 3

While non of the above solutions was fitting my purpose, this worked for me.

var pattern = @"^(-?[1-9]+\d*([.]\d+)?)$|^(-?0[.]\d*[1-9]+)$|^0$|^0.0$";
return Regex.Match(value, pattern, RegexOptions.IgnoreCase).Success;

Example of valid values: "3", "-3", "0", "0.0", "1.0", "0.7", "690.7", "0.0001", "-555", "945465464654"

Example of not valid values: "a", "", " ", ".", "-", "001", "00.2", "000.5", ".3", "3.", " -1", "--1", "-.1", "-0", "00099", "099"

Answer 4

Regex regex = new Regex ("^[0-9]{1,4}=[0-9]{1,4]$")

Answer 5

Here is my working one:

^(-?[1-9]+\\d*([.]\\d+)?)$|^(-?0[.]\\d*[1-9]+)$|^0$

And some tests

Positive tests:

string []goodNumbers={"3","-3","0","0.0","1.0","0.1","0.0001","-555","94549870965"};

Negative tests:

string []badNums={"a",""," ","-","001","-00.2","000.5",".3","3."," -1","--1","-.1","-0"};

Checked not only for C#, but also with Java, Javascript and PHP

Answer 6

It is matching because it is finding "a match" not a match of the full string. You can fix this by changing your regexp to specifically look for the beginning and end of the string.

^\d+$