Sample 1b: Adding Regular Expression Validation an Alternative Way Summary Two samples are covered in this article: creating a custom Text Box that performs regular expression validation, and creating an extender provider that uses a different method to perform the same regular expression validation.In the overview article, I showed you how to quickly enhance the Text Box control to accept only numeric data, creating a new control with a minimum amount of work on your part. Regular Expressions because we will use a regular expression to match the pattern of the URL and the inputted URL in the textbox using Is Match method. We will have to initialize pattern as String to hold a string value of http(s)? The Button1_click here will trigger to decide if the inputted URL in the textbox is valid or not. Duncan Mackenzie Microsoft Developer Network May 2002 Summary: Covers the basics of inheriting from another control and adding your own properties, methods, and events along with adding your own code; one of a series of Microsoft Windows Forms control development samples to be read in conjunction with associated overview article. This article is the second in a five-article series on developing controls in Microsoft® .NET: Introduction Sample 1a: Adding Regular Expression Validation to the Text Box Control A Short Discussion on Regular Expressions What Do I Need to Build?Bottom line for these two examples is that I like to use the example expressions found in an article on Net Tuts /and modify them to meet my needs.
:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9] )(? The PHP filter_var function has only been available since PHP 5.2.If you are running a PHP version older than 5.2 you are out of luck.If you are uncertain and looking for a guide then this may help: If you are using a version of PHP that is older than PHP 5.2: - Use the regular expression approach If you are using PHP 5.2.13 or PHP 5.3.2 and need URLs with dashes to validate: - Use the regular expression approach If you don't fall into one of the above categories: - Use the filter_var() approach Note: Some have complained that using the PHP filter_var() function is too permissive and allows URLs that should not validate.One solution is to use filter_var for your initial validation and then perform additional validation checks if the original filter_var validation passes.