Use the CompareTo method with another String. : String Compare « Data Type « VB.Net Tutorial

Imports System

Public Class MainClass

    Public Shared Sub Main()
        Dim strFirst As String = "Goodbye"

        Console.WriteLine(CompareStrings(strFirst, strFirst))
    End Sub
    Private Shared Function CompareStrings(str1 As String, str2 As String) As String
        Dim cmpVal As Integer = str1.CompareTo(str2)
        If cmpVal = 0 Then
            Return "The strings have the same value!"
        Else
            If cmpVal > 0 Then
                Return "The first string is greater than the second string!"
            Else
                Return "The second string is greater than the first string!"
            End If
        End If
    End Function
End Class

2.31.String Compare
	2.31.1.	Comparing strings: Equals, =, String.Equals() and CompareTo
	2.31.2.	String Equals with overloaded operator, member method and static member method
	2.31.3.	String Compare with case sensitive and insensitive
	2.31.4.	Compare String value in If statement
	2.31.5.	Whether a string is the prefix or suffix of another string.
	2.31.6.	Use the CompareTo method with another String.
	2.31.7.	Use String.Compare to check if a URI is a file URI
	2.31.8.	Compare two strings using different CompareOptions settings.