mysql - PHP Check if string contains a letter

Question

I am creating a login and want to allow my users to login either by username or email. How would I check if a string contains a letter, in this case @ so I can handle it correctly. Would I use strstr or strpos? Thanks!

Answer 1

To just check if string contains a letter you could use

if (strpos($source_string, $letter) !== false) { ... }