How to check for null value in vb

If a reference may be Nothing, we must test before using its members. When a Module or Class is created, the fields within it are automatically set to Nothing. You never need to assign them to Nothing at creation time. Tip Variables in VB. NET never have garbage values. In managed code, like the. NET Framework, initial values are 0 or Nothing. NET program that uses module-level field. Nothing can be used with value types such as Integers. When used on values, "Nothing" indicates the default value for the type.

So an Integer assigned to Nothing is zero. Tip Structures are too a value type. When we assign them to Nothing, we get an empty Structure with no bits set to 1. A string in VB. NET can be assigned to Nothing, which is the same concept as Null. We can test a Nothing String with the String. IsNullOrEmpty method. Tip The term "null" is simply a different name for "Nothing. This function can be used in any subprocedure and function procedure.

You are free to use this image on your website, templates etc, Please provide us with an attribution link How to Provide Attribution? The below code is the demonstration code for you. Now check whether the empty value is NULL or not. Below code is to test whether the empty string is NULL or not. How to VB. What is VB. NET null?

What is an Empty Strings? Length When run the above code it will throw NullReferenceException. How to check null String in vb. NullReferenceException Next : How to vb. Download Source Code. Print Source Code. Object, ByVal e As System. EventArgs Handles Button1.