How to allow only 3 digit and one dot in Regular Expression

Question

I want to do like this : 3.40 and not more than 3 characters and one dot:

<md-input-container class="md-block">
                    <label>Marks/CGPA</label>
                    <input type="text" name="education.cgpa" ng-model="education.cgpa"
                           ng-pattern="/^[0-9]{0,4}$/">
                    <div class="input-validation" ng-show="educationSaveForValidate['education.cgpa'].$error.pattern">
                        Insert valid CGPA
                    </div>
                </md-input-container>

How can I allow only 3 digits and one dot in Regular Expression?

score 3 · Answer 1 · answered Jul 31 '17 at 11:18

3

You may use a single regex like

ng-pattern="/^(?!.{5})\d*\.?\d+$/"

or - to allow an empty string:

ng-pattern="/^(?!.{5})\d*\.?\d*$/"

You may also move the length check out of the regex:

ng-pattern="/^\d*\.\d*$/" ng-maxlength="4"

Details

^ - start of string
(?!.{5}) - a negative lookahead that fails the match if there are any 5 chars in the input string
\d* - 0+ digits
\.? - an optional .
\d* - zero or more digits (if \d+ is used, then 1 or more digits)
$ - end of string.

To disallow any leading/trailing spaces, add ng-trim="false".

answered Jul 31 '17 at 11:18

Wiktor Stribiżew

607,720
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thanks Wiktor Stribiżew. your code does not work properly for me. but i have found a solution. this is : ng-pattern="/^\d\.\d{0,2}$/" – monir tuhin Jul 31 '17 at 11:38
@monirtuhin That won't allow valid float numbers like `.123`. Also, that won't match `12.4`. And that will match `1.` (no idea if that is important here). – Wiktor Stribiżew Jul 31 '17 at 11:39
I wanted one digit befor dot(.) and two digit after dot(.) like (2.50) . in this way this solution helped me. thanks wiktor – monir tuhin Jul 31 '17 at 11:44
@monirtuhin There are no exact requirements in the question, so my answer is valid. Yours is too restricted. If my answer helped, feel free to upvote it. – Wiktor Stribiżew Jul 31 '17 at 11:50
1

your answer also helped me to identify my problem. thanks – monir tuhin Jul 31 '17 at 11:53

score 0 · Answer 2 · answered Jul 31 '17 at 11:35

0

https://regex101.com/r/kF0hJ5/17

Check this link above, I hope it'll help you. Sorry for commenting link here. Doing so as I have less repo.

answered Jul 31 '17 at 11:35

score 0 · Answer 3 · answered Jul 31 '17 at 11:37

0

i have solved my problem this way......

ng-pattern="/^\d\.\d{0,2}$/"

answered Jul 31 '17 at 11:37

monir tuhin

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3
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`/^\d\.\d{0,2}$/` won't allow valid float numbers like `.123`. Also, that won't match `12.4`. And that will match `1.` (no idea if that is important here). – Wiktor Stribiżew Jul 31 '17 at 11:40
@ Wiktor Stribiżew I wanted one digit befor dot(.) and two digit after dot(.) like (2.50) . in this way this solution helped me. thanks – monir tuhin Jul 31 '17 at 11:51

How to allow only 3 digit and one dot in Regular Expression

3 Answers3