String.Format() JavaScript equivalent to .NET

Here is a JavaScript function to format strings on the Client-Side as if you were using in the the .NET String.Format() method in your code-behind.

String.Format = function()
{


    // Check for arguments
    if( arguments.length == 0 ) return null;
    // Get the string which is the first argument
    var stringToFormat = arguments[0];
    for(var i=1; i < arguments.length;i++)
    {
        var replaceExpression = new RegExp('\\{' + (i-1) + '\\}','gm');
        // Replace argument
        stringToFormat = stringToFormat.replace(replaceExpression, arguments[i]);
    }

    // Return the formated string
    return stringToFormat;

}

Alternative you can used the JavaScript prototype framework 'Template' object to do string formatting using variable names instead of argument indexes.

See http://prototypejs.org/api/template for the Template object API.