String truncation problems

How does string truncation problem 19850523 become a form like? My current practice is to use substr () three times. Is there a simple way ?, Regular expression: vars = & quot; 19850516 & quot; s = s. replace (/(\ d {4 string truncation problem
How did 19850523 become a form like?
My current practice is to use substr () three times ()
Is there a simple way?

------ Solution --------------------
Regular expression:

Var s = "19850516 ";
S = s. replace (/(\ d {4}) (\ d {2}) (\ d {2})/, "$1-$2-$3 ");
Alert (s );
------ Solution --------------------
It looks like a date string. use the date function.
$ Str = '000000 ';
Echo date ('Y-m-D', strtotime ($ str ));