Alphanumeric, Integer Only and other popular RegEx for JavaScript
Alphanumeric (only small case alphabets and numbers) Regex - /^[a-z0-9]+$/i
Alphanumeric (small case alphabets, upper case and numbers) Regex - /^[a-zA-Z0-9]+$/i
Alphanumeric (small case alphabets, upper case, numbers and white space) Regex - /^[a-zA-Z0-9 ]+$/i