Copy and Concatenate String in VB.NET

The Concat method adds strings (or objects) and returns a new string. Using Concat method, you can add two strings, two objects and one string and one object or more combination of these two.

The following source code concatenate two strings.

    Dim str1 As String = "ppp"
    Dim str2 As String = "ccc"
    Dim strRes As String = [String].Concat(str1, str2)
    Console.WriteLine(strRes)

The following source code concatenates one string and one object.

    Dim str1 As String = "ppp"
    Dim strRes As String
    Dim obj As Object = DirectCast(12, Object)
    strRes = [String].Concat(str1, obj)
    Console.WriteLine(strRes)

The Copy method copies contents of a string to another. The Copy method takes a string as input and returns another string with the same contents as the input string. For example, the following code copies str1 to strRes.

    Dim str1 As String = "ppp"
    Dim strRes As String = [String].Copy(str1)
    Console.WriteLine("Copy result :" & strRes)

The CopyTo method copies a specified number of characters from a specified position in this instance to a specified position in an array of characters. For example, the following example copies contents of str1 to an array of characters. You can also specify the starting character of a string and number of characters you want to copy to the array.

    Dim str1 As String = "ppp"
    Dim chrs As Char() = New [Char](1) {}
    str1.CopyTo(0, chrs, 0, 2)
    Console.WriteLine(chrs)

The Clone method returns a new copy of a string in form of object. The following code creates a clone of str1.

    Dim str1 As String = "ppp"
    Dim objClone As Object = str1.Clone()
    Console.WriteLine("Clone :" & objClone.ToString())

The Join method is useful when you need to insert a separator (String) between each element of a string array, yielding a single concatenated string. For example, the following sample inserts a comma and space (", ") between each element of an array of strings.

    Dim str1 As String = "ppp"
    Dim str2 As String = "ccc"
    Dim str3 As String = "kkk"
    Dim allStr As String() = New [String]() {str1, str2, str3}
    Dim strRes As String = [String].Join(", ", allStr)
    Console.WriteLine("Join Results: " & strRes)

Conclusion