Takes the input and makes sure all non numeric characters are removed.
Keeps only the digits in a value and removes everything else: letters, spaces, dashes, brackets, plus signs, and even decimal points are all stripped out, leaving the bare digits joined together. Use this to pull a clean number out of a formatted value, for example to reduce a phone number written with spaces and brackets to digits only, or to strip the letters from an order code. Because only digits remain, the result comes back as a plain number, so any leading zeros are dropped.