& lt？ Server-side programming language (abbreviation of professional hypertext preprocessor)

$ str = ' 12 | string '；

echo(int)$ str；

//output 12

If you like conventional solutions.

& lt？ Server-side programming language (abbreviation of professional hypertext preprocessor)

$ str = ' 12 | string '；

echo preg_replace('/(\d+)。 */'，' \\ 1 '，$ str)；