Using REGEX in Validations

Recently I saw many questions on Discussion Boards regarding validations. Folks always want to go with validations avoiding Apex.


We can not ignore flexibility provided by Apex but I always prefer Validation when I can implement my business logics with it. I am bit lazy kind of person and hate writing test methods, that's why I use validation because if there is no code then no test method. Thanks to Salesforce for providing these kind of native functionalities where I do not have to write any code.


I am going bit off track as there is no point discussing over this. So coming back to REGEX in Validations, I have some good examples.


Example 1 : Validate Credit Card Number
Description :
Validates that a custom text field called Credit_Card_Number is formatted in 9999-9999-9999-9999 or 9999999999999999 number format when it is not blank.The pattern specifies:
• Four digits (0-9) followed by a dash: \\d{4}-
• The aforementioned pattern is repeated three times by wrapping it in () {3}
• Four digits (0-9)
• The OR character (|) allows an alternative pattern of 16 digits of zero through nine with no dashes: \\d{16}


Validation Formula :

NOT( REGEX( Credit_Card_Number__c ,
"(((\\d{4}-){3}\\d{4})|\\d{16})?"))

Error Message : Credit Card Number must be in this format: 9999-9999-9999-9999 or 9999999999999999.


Example 2 : Valid IP Address
Description :
Ensures that a custom field called IP Address is in the correct format, four 3-digit numbers (0-255) separated  by periods.

Validation Formula :

NOT(
REGEX( IP_Address__c,
"^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$"
))

Error Message : IP Address must be in form 999.999.999.999 where each part is between 0 and 255.


Example 3 : US Phone Number Has Ten Digits
Description :
Validates that the Phone number is in (999) 999-9999 format. This works by using the

REGEX function to check that the number has ten digits in the (999) 999-9999 format.


Validation Formula : 

NOT(REGEX(Phone, "\\D*?(\\d\\D*?){10}"))

Error Message : US phone numbers should be in this format: (999) 999-9999.


Example 4 : Social Security Number Format
Description :
Validates that a custom text field called SSN is formatted in 999-99-9999 number format

(if it is not blank). The pattern specifies:
• Three single digits (0-9):\\d{3}
• A dash
• Two single digits (0-9):\\d{2}
• A dash
• Four single digits (0-9):\\d{4}


Validation Formula :

NOT(
OR(
LEN (Social_Security_Number__c) = 0,
REGEX( Social_Security_Number__c , "[0-9]{3}-[0-9]{2}-[0-9]{4}")
))

Error Message : SSN must be in this format: 999-99-9999.


This will provide am idea how we can write validations using REGEX.


Cheers.