Php regular expression unless a number

Evaluate a php regular expression unless a number is used to obtain a regular expression, unless the number is: & quot; a1asd2asd3a & quot; after regular expression filtering, output 123 not intval () or (int) if the number is greater than 10 digits, then no one will reply to the correct message and then send it to you. ------ solution -------------------- echopreg_replace (D, a1asd2asd)
Calculate a regular expression unless the number is:
"A1asd2asd3a"
Output after regular expression filtering
123

Do not use intval () or (int) because it cannot work if it is greater than 10 digits.
Who will reply to you first?

------ Solution --------------------
Echo preg_replace ('/\ D/', '', 'a1asd2asd3a ');