Question

I’m trying to replace an ASP.NET (C#) server-sided method by an javascript/Jquery method. I’m fairly new to Jquery but all went well until I began with regular expressions.

my code in ASP.NET C#

if ((Regex.Match(postcode.Trim(), @"^[1-9]\d{3} ?[a-zA-Z]{2}$")).Success)
    {
       return Regex.Replace(postcode.Trim(), @"(^[1-9]\d{3})( ?)([a-zA-Z]{2}$)", "$1$3").ToUpper();
    }
    else
    {
       throw new Exception("Postcode incorrect");
    }

in Jquery I’m only focussing to replace for the moment by manually input the right strings.

I’ve created a function like:

function FormatDutchPostalCode() {
   var postcode = $("#Text1").val();
   postcode = postcode.replace(/(^[1-9]\d{3})( ?)([a-zA-Z]{2}$)/, $1$3);
   $("#Text1").val(postcode);
}

I’m getting the value from the textbox, so far so good. But when replacing it seems the browsers exits the function (tested in IE9 and FF10.0.1)

What I’m i doing wrong and is it possible to troubleshoot Jquery/Javascript. I’ve seen firebug could set breakpoints but I can’t find if (and if so which) errors occur.

Answer 1

Here is a port of your C# function to JS. It uses an IIFE in order to cache the regex without polluting the current execution scope.

jsFiddle

var FormatDutchPostalCode = (function() {
    var reg = /^([1-9]\d{3})\s?([a-z]{2})$/i;
    return function(){
        var postcode = $.trim($("#Text1").val());
        if (postcode && postcode.match(reg) )
        {
            return postcode.replace(reg, "$1$2").toUpperCase();
        }
        else
        {
            throw new Error("Postcode incorrect");
        }
    };
}());