The ToLower() method is used if all characters in a string variable in the Visual Basic programming language are to be converted to lowercase.

Let's examine the example below..

Module ModuleTest Sub Main() Dim str As String = "YAZİLim" Console.WriteLine(str.ToLower()) Console.WriteLine(str) Console.ReadLine() End Sub End Module

In the screen output, our YAZİLim value has changed to yazilim.

Note : The point that should not be forgotten here is that the value of our string variable still remains as "YAZİLim". Only the value has changed during the use on the method. We can see this in the screenshot.