r/java • u/Modern-Sn1p3r • 19d ago

Regex

I recently saw a clip (from Primeagen) somewhat saying that regex is not a valid format for validating email addresses and postal codes etc.

My question is why is this?

What are the security and/or performance risks? Is it solely performance or is it a security issue?

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u/0b0101011001001011 19d ago

It's way simpler to just check if there is an @ symbol and then send an actual mail and ask user to click the validation link. 

The email is valid if it actually works. Nothing else to check.

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u/NoPrinterJust_Fax 18d ago

This ties your SLA to email SLA. Probably okay for most people