Visual Basic 2008 Recipes: A Problem-Solution Approach

2.5. Validate Input Using Regular Expressions

Problem

You need to validate that user input or data read from a file has the expected structure and content. For example, you want to ensure that a user enters a valid IP address, telephone number, or e-mail address.

Solution

Use regular expressions to ensure that the input data follows the correct structure and contains only valid characters for the expected type of information.

How It Works

When a user inputs data to your application or your application reads data from a file, it's good practice to assume that the data is bad until you have verified its accuracy. One common validation requirement is to ensure that data entries such as e-mail addresses, telephone numbers, and credit card numbers ...