01-has-number.php - returns true if the given string contains a digit

02-mi5.php - returns true if the given string is 00 followed by a digit

03-z-or-Q.php - returns true if the given string contains the letter q or z (uppercase and lowercase)

04-phone-number.php - returns true if the given string contains only numbers and hyphens

05-split-into-words.php - splits a sentence into just words

06-three-Os.php - returns true if a string contains three or more o or O characters in a row

tricksy-01-valid-email.php - takes a string, trims any whitespace at the beginning/end of the string (using preg_replace) and then returns if the trimmed string is a valid email