JavaScript Date number Regular expression

Web Effects date number Regular expression

The number is regular
/^d{3,4}-d{7,8} (-d{3,4})? $/
The area code must be filled with a 3-4-digit number, followed by "-" and the telephone number

^d{3,4}-
Number with 7-8 digits

d{7,8}
The number of the extension number is 3-4 digits, not required, but if filled with "-" and telephone number to connect

(-d{3,4})?

<script type= "Text/javascript" >
function Testrgexp (Re, s) {//Parameter description Re is regular expression s for the character to be judged
return Re.test (s)
}
var re =/^[0-9]*[1-9][0-9]*$/;
To determine whether a positive integer note: The program is the expression format:/The above regular expression (without double quotes)/
var s = prompt ("Please enter the character to be judged", 10);
var result = Testrgexp (re, s); Test returns TRUE or False
alert (result);
</script>

var r =/^[0-9]*[1-9][0-9]*$///Positive integer
R.test (str); STR for you to judge the character execution returns the result true or false

function Testrgexp (Re, s) {//Parameter description Re is regular expression s for the character to be judged
return Re.test (s)
}

<

script type= "Text/javascript" >
 function isdigit (str) {
  var reg =/^d*$/;
  return reg.test (str);
 }
 var str = "7654321";
 document.write (IsDigit (str));
 var str = "Test";
 document.write (IsDigit (str));
 </script>