Extract digits from string - Google spreadsheet

Question

In Google spreadsheets, I need a formula to extract all digits (0 to 9) contained into an arbitrary string, that might contain any possible character and put them into a single

Answer 1

If some of source cells may contain only numbers it is safer to convert the value to text first, then regexreplace. Otherwise it produces error.

Result as text

=REGEXREPLACE(TO_TEXT(C1),"\D+", "")

Result as number

=VALUE(REGEXREPLACE(TO_TEXT(C1),"\D+", ""))

The same for whole column

=ARRAYFORMULA(IF(LEN(C1:C), VALUE(REGEXREPLACE(TO_TEXT(C1:C),"\D+", ""))))