That may seem like Captain Obvious speaking, but you’ll be amazed at some of the data that gets entered into a name field. Validating NamesĪ name doesn’t generally contain weird symbols, and definitely not numbers. Based on each of these variables’ values, we will know if the data is correct or not. These objects will determine if all our data is valid or not. Private EmailValid As Boolean 'Is Email Valid? Private PhoneValid As Boolean 'Is Phone Number Valid? Private SurnameValid As Boolean 'Is Surname Valid? The Regular Expression’s functionalities exist in the namespace, so let us add that first: Imports ' Regular Expressions NamespaceĪdd the following four variables inside the General Declarations section: Private NameValid As Boolean 'Is Name Valid? Start Visual Studio and create a Desktop VB.NET application and design the form to resemble Figure 1.
Also, the more tests you are performing, the slower your app might become. Well, sometimes a good structured and thought out If statement can suffice, but it can become quite long and cumbersome in the future. There are some more tests, but I want to keep this article straightforward and basic enough. For example : If you are only supposed to type in 50 characters, you must not be able to enter more than fifty. Range test – This tests checks to see if entered values are within a specified range.For example: If a user is supposed to enter a name, numbers and some special symbols must not be allowed. Permitted Character test – This test ensure that no illegal characters are entered.For example: Integers of dates that do not need conversion afterwards. Type test – This test checks if the input is the correct type.Format test – This test determines if the entered string is in the correct format.Determining whether or not data is valid can sometimes be a painstaking process as there are numerous tests that need to be thought of. In simple terms, validation refers to ensuring entered data is well, valid.
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Today you will learn how to use regular Expressions to validate user input. This is why I decided to make use of Regular Expressions here within this article. Because everyone has a different way of doing things, my methods might not be 100% the same as your methods. Validating user input can be quite a pain, especially if you do not know what techniques and what namespaces are at your disposal.
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