Char

In VB.NET programs the Char type is useful. Chars are value types—this means they are located in the bytes on the evaluation stack.

Char notes

You can get individual Chars from a String variable. One point of confusion occurs when converting Chars to Integers.

String example

Strings are composed of individual characters. With a special syntax, we can get these Chars. You cannot assign Chars at indexes inside a string.

Module Module1
    Sub Main()
        ' String variable.
        Dim s As String = "Delete"

        ' Char variable.
        Dim c As Char = "D"c

        ' Test first character of String.
        If c = s(0) Then
            Console.WriteLine("First character is {0}", c)
        End If
    End Sub
End Module
First character is D

Char, Integer

In many programming languages, you can cast a Char to an Integer. In the VB.NET language, we must use a built-in conversion function.

Module Module1
    Sub Main()
        Dim a As Char = "a"
        Dim b As Char = "b"

        Dim i As Integer = Asc(a)
        Dim i2 As Integer = AscW(b)

        Console.WriteLine(i)
        Console.WriteLine(i2)
    End Sub
End Module
97
98

Byte size

In VB.NET and C#, Chars are 2 bytes. This means they can accommodate values outside of the ASCII range. But it may also cause more memory usage.

Summary

The Char type is used with the String type. When possible, manipulating and handling Chars is preferable to Strings because they are values, not reference types.

Final notes

Chars use less memory than a one-character String. Despite this, compatibility and correctness are most important in a VB.NET program.