# Required Number of Digits/Characters

**URL:** <https://community.tulip.co/t/required-number-of-digits-characters/1795>\
**Category:** Support, Troubleshooting, & Help\
**Created:** [February 9, 2021, 8:50pm UTC](https://community.tulip.co/t/required-number-of-digits-characters/1795 "2021-02-09T20:50:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![lorenzo\_SNN](https://avatars.discourse-cdn.com/v4/letter/l/e0b2c6/32.png) [@lorenzo\_SNN](https://community.tulip.co/u/lorenzo_SNN)\
**Post date:** [February 9, 2021, 8:50pm UTC](https://community.tulip.co/t/required-number-of-digits-characters/1795/1 "2021-02-09T20:50:52Z")

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Hello,

I’m looking to require a specific number of digits or characters for an operator input. Is there a way to set this up?

Thanks!

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**Author:** ![Kailey](https://sea2.discourse-cdn.com/flex020/user_avatar/community.tulip.co/kailey/32/5386_2.png) [@Kailey](https://community.tulip.co/u/Kailey)\
**Post date:** [February 9, 2021, 8:57pm UTC](https://community.tulip.co/t/required-number-of-digits-characters/1795/2 "2021-02-09T20:57:30Z")

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Hey Lorenzo,

Thanks for posting in Tulip Community!

The best way to build this functionality will be to use Regular Expressions. Here’s an example app that I just built:

Here the input variable is called: **idTest**  
The goal is to make sure the operator input’s an ID to **idTest** that is exactly 3 characters, and is made up of characters from A-Z.

Here’s the trigger I built to achieve that goal:

 ![Screen Shot 2021-02-09 at 3.55.36 PM](https://us1.discourse-cdn.com/flex020/uploads/agilemfg/original/2X/2/210d5c5ec84d737f6eb04ec62e640fc8ea477d55.jpeg)

Examples:  
‘ABC’ will match the RegEx, and the app will move to the next step  
‘TR’ will fail the RegEx and show message.

Here’s a great RegEx resource: [https://regexr.com/](https://regexr.com/)

Please let me know if you have questions about this!

Thanks,  
Kailey