How to check if string has at least one letter, number and special character in php

Question

I am currently writing a small script that checks the contents of each string.

I was wondering what the REGEX would be to make sure that a string has a letter (upper

Answer 1

It may be best to use 3 distinct regexs to do this, since you would need to match 6 different possibilities, depending on where your special characters are in your string. But if you want to do it in one regex, and your special characters are, say, [+?@], it is possible:

$string = "abc@123";
$regex = "/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$%^&]).*$/"
if (preg_match($regex, $string)) {
   // special characters
}