JS Regular expression of the detailed

Source: Internet
Author: User
Keywords nbsp regular expression checksum beginning letter
Tags beginning expression function java code login name return string


Whether the checksum is composed entirely of digits

function IsDigit (s)
{
var patrn=/^[0-9]{1,20}$/;
if (!patrn.exec (s)) return false
return True
}


Verify Login Name: Can only enter 5-20 letters beginning with the letter, can be with the number, "_", "." The string

Java code function Isregisterusername (s) {var patrn=/^[a-za-z]{1} ([a-za-z0-9]|[.   _]) {4,19}$/; if (!patrn.exec (s)) return false return True}



Verify user name: You can enter only 1-30 strings that start with a letter

Java code

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