A simple way to determine whether the input string is a date format _javascript tips

The example below is as follows:

function IsDate (datestring) {
  if (Datestring.trim () = "") return true;
  var r=datestring.match (/^ (\d{1,4}) (-|\/) (\d{1,2}) \2 (\d{1,2}) $/); 
  if (r==null) {
   alert ("Please enter a properly formatted date \n\r date format: yyyy-mm-dd\n\r example  : 2008-08-08\n\r");
  return false;
  }
  var d=new Date (R[1],r[3]-1,r[4]);  
  var num = (d.getfullyear () ==r[1]&& (D.getmonth () +1) ==r[3]&&d.getdate () ==r[4]);
  if (num==0) {
   alert ("Please enter a properly formatted date \n\r date format: yyyy-mm-dd\n\r example  : 2008-08-08\n\r");
  }
  return (num!=0);
 } 

The above decision to enter the string is a date format is a simple way to share all the content of the small, hope to give you a reference, but also hope that we support the cloud-dwelling community.