Is Null Or Empty(str Phone Num) Then Phone Valid = re Phone. Text) Then 'Call Phone Validation Function Message Box. I set up my Expression to allow only numbers, but in the format I explained earlier.
This means that as a programmer, you have the power to supply the exact pattern for the input you desire in any text input field. Again, certain special characters are obviously not allowed.
They make use of a pattern matching system to match the input with a certain pattern of data.
Add the following inside your name Textbox's Leave event: Private Sub txt Name_Leave(sender As Object, e As System. Leave 'If Not A Matching Format Entered If Not Regex. If you are uncertain about the pattern I supplied, have a look here. Just a note, some surnames contain spaces and even hyphens. Sometimes there are even brackets surrounding the code.
My surname contains a space and it can get quite frustrating if I am not allowed to enter my correct surname, or that I have to edit my surname not to include a space. In certain cases the international dialling code will also need to be supplied. Compiled _ ) Dim bln Possible Match As Boolean = re Email. Text) If bln Possible Match Then 'Check If Entered Email Is In Correct Format If Not txt Email.
Well, sometimes a good structured and thought out If statement can suffice, but it can become quite long and cumbersome in the future. By using Regular Expressions this way, you can reduce the chances of getting errors at erratic times. This sub checks the email's format and if it thinks that it matches, it returns True and vice versa.Also, the more tests you are performing, the slower your app might become. For more information regarding Regular Expressions, you are welcome to look at these two MSDN articles: Because it is always easy to learn by doing things practically, you will be creating an app that makes use of Regular Expressions to determine valid input. NET application and design the form to resemble Figure 1. Obviously this only works for the formatting of the email.