angularjs ng-pattern regex for 4 digits and 2 decimal

Question

I am trying to create a Regex for a number with maximum 4 digits and if the input has decimal it has to have 2 digits - .20 and not .1. tried:

ng-pattern="/^[0-9]+(\.[0-9]{1,2})?$/" //fail for 666666, .10, .1

Examples for valid inputs:

100.10
100
3000.10

Example for invalid:

10000 //has more then 4 digits before decimal
100.1 //has only 1 digit after decimal
.10 //has no digits before decimal

Thanks for any help.

ProfDFrancis · Accepted Answer · 2017-10-01 08:16:20Z

3

Use {#,#} to limit the number of digits to 1 to 4

Try

^[0-9]{1,4}(\.[0-9][0-9])?$

Use ( )? to make an optional two-digit decimal part

The problem with using the {1,2} is that it allows one or two digits, when you really only want two. And I assume you want to enforce a rule that if they have a ".", they must have two digits?

For example

var patt = /^[0-9]{1,4}(\.[0-9][0-9])?$/i

"1011.11".match(patt)!==null
"1011.1".match(patt)!==null

Returns

true
false

With gratitude to Sebastian Proske and Wiktor Stribiżew

For pointing out the need to escape the .

edited Oct 1, 2017 at 8:16

answered Oct 1, 2017 at 7:52

ProfDFrancis

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7 Comments

Itsik Mauyhas Over a year ago

Parsing error - angular.min.js:123 Error: [$parse:lexerr] errors.angularjs.org/1.6.3/$parse/……=s%200-0%20%5B%5E%5D&p2=%5E%5B0-9%5D%7B1%2C4%7D(.%5B0-9%5D%5B0-9%5D)%3F%24

ProfDFrancis Over a year ago

Really strange. How about just in a browser?

Itsik Mauyhas Over a year ago

well for ng-pattern the format is ng-pattern="/^[0-9]{1,4}(.[0-9][0-9])?$/g" so it works great. thanks.

Itsik Mauyhas Over a year ago

@SebastianProske just tested 1a22 with ng-pattern and it was invalid as expected.

ProfDFrancis Over a year ago

Ah yes thanks Sebastian. Its a nasty feature of regex that in different versions, the parentheses, dots etc have to be escaped or not escaped. Sorry. I will add to answer. Turns out (by chance!) that I got it right for Itsik's case but your point is important for others.

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angularjs ng-pattern regex for 4 digits and 2 decimal

1 Answer 1

Use {#,#} to limit the number of digits to 1 to 4

Use ( )? to make an optional two-digit decimal part

For example

With gratitude to Sebastian Proske and Wiktor Stribiżew

7 Comments

Your Answer

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Collectives™ on Stack Overflow

1 Answer 1

Use {#,#} to limit the number of digits to 1 to 4

Use ( )? to make an optional two-digit decimal part

For example

With gratitude to Sebastian Proske and Wiktor Stribiżew

7 Comments

Your Answer

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