Javascript regex to allow numbers and special characters like dot(.) and colon (:) for validating specific hostnames

Question

I have below host name and i want regex for the same

127.0.0.1:8181

The input contains numbers, dot(.) and colon (:)

I used below regex, but none of them worked

^([0-9]|#|+|*)+$
^[0-9*#+]+$

Adding my code snippet below

var guidRegex = new RegExp("/[0-9.:]+/")
var hostName = "127.0.0.1:8181";
var match = guidRegex.test(hostName);

After executing the value of match is FALSE

See for example https://stackoverflow.com/questions/34438566/regex-pulling-ip-and-port-from-string or https://stackoverflow.com/questions/2908740/java-regex-matching-ip-address-and-port-number-as-captured-groups or https://stackoverflow.com/questions/23542035/how-to-modify-regular-expression-for-ipport — The fourth bird, Apr 13 '20 at 07:04

score 1 · Answer 1 · answered Apr 13 '20 at 07:04

1

Try:

^\d+(?:\.\d+){3}(?::\d+)?$

Demo

This will match an IPv4 address, along with an optional port number appearing at the end.

answered Apr 13 '20 at 07:04

Tim Biegeleisen

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Sohail Ashraf · Answer 2 · 2020-04-13T07:20:30.590

1

To validate a string with numbers . and :.

let str = '127.0.0.1:8181';
console.log(/[0-9.:]+/g.test(str));

To validate IPV4 ips addresses:

let str = '127.0.0.1:8181';
console.log(/[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}:([0-9]+)?/g.test(str));

//OR

console.log(/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}(:[0-9]+)?$/g.test(str));

edited Apr 13 '20 at 07:20

answered Apr 13 '20 at 07:04

Sohail Ashraf

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you mean the regex is just "/[0-9.:]+/" – Ajithesh Gupta Apr 13 '20 at 07:13
yes, to validate a string with `number , . and : , but it will not validate ip adress, for taht you could use the second solution – Sohail Ashraf Apr 13 '20 at 07:15
I have updated my code above, and the regex which you gave is not working. Can you please let me know – Ajithesh Gupta Apr 13 '20 at 09:22
Sure, let me check – Sohail Ashraf Apr 13 '20 at 09:29
You don't need to add `/` slash when creating with `new Regex()` . Try this. `new RegExp("[0-9.:]+")` – Sohail Ashraf Apr 13 '20 at 09:35
these are the syntax you can use. `new RegExp(/ab+c/, 'i') // literal notation` or `new RegExp('ab+c', 'i') // constructor` – Sohail Ashraf Apr 13 '20 at 09:38

Javascript regex to allow numbers and special characters like dot(.) and colon (:) for validating specific hostnames

2 Answers2

Demo