regex for numbers and special characters code example

Example 1: regex for number and letters

let regex = /[^A-Za-z0-9]+/

Example 2: regex check from a-z 0-9

myString.match(/^[A-Za-z0-9_.]+$/)

Example 3: regex match numbers and special characters

echo %H1E2L+L#O! | sed 's/[^A-Z!]//g'	#replaces number and special
characters which aren't ! or an uppercase letter A-Z