Sys.StringBuilder Class

Sys.StringBuilder Class
This page is specific to:.NET Framework Version:3.54.0

Provides a mechanism to concatenate strings.

Namespace: Sys

Inherits: None

var stringBuilderVar = StringBuilder(string);

Constructors

Sys.StringBuilder Constructor: Creates a new instance of StringBuilder and optionally accepts initial text to concatenate.

Members

Sys.StringBuilder append Method: Appends a string to the end of the StringBuilder instance.
Sys.StringBuilder appendLine Method: Appends a new string with a line terminator to the end of the StringBuilder instance.
Sys.StringBuilder clear Method: Clears the contents of the StringBuilder instance.
Sys.StringBuilder isEmpty Method: Determines whether the StringBuilder instance has any content.
Sys.StringBuilder toString Method: Creates a string from the contents of a StringBuilder instance.

Remarks

The StringBuilder class represents a mutable string of characters and provides a mechanism to concatenate a sequence of strings.

Example

The following example shows how to create a new StringBuilder instance and call the append method to add a line of text. The code then calls the appendLine method to add a string with a line terminator at the end of the string. Finally, the code calls the toString method, passing a "|" character as a delimiter to insert between the elements of the string returned by StringBuilder.

C++

JScript

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Imports System.Text

Public Module App 
    Public Sub Main() 
        ' Create a StringBuilder that expects to hold 50 characters.
        ' Initialize the StringBuilder with "ABC".
        Dim sb As New StringBuilder("ABC", 50)

        ' Append three characters (D, E, and F) to the end of the StringBuilder.
        sb.Append(New Char() {"D"c, "E"c, "F"c})

        ' Append a format string to the end of the StringBuilder.
        sb.AppendFormat("GHI{0}{1}", "J"c, "k"c)

        ' Display the number of characters in the StringBuilder and its string.
        Console.WriteLine("{0} chars: {1}", sb.Length, sb.ToString())

        ' Insert a string at the beginning of the StringBuilder.
        sb.Insert(0, "Alphabet: ")

        ' Replace all lowercase k's with uppercase K's.
        sb.Replace("k", "K")

        ' Display the number of characters in the StringBuilder and its string.
        Console.WriteLine("{0} chars: {1}", sb.Length, sb.ToString())
    End Sub
End Module

' This code produces the following output.
'
' 11 chars: ABCDEFGHIJk
' 21 chars: Alphabet: ABCDEFGHIJK

Reference

new Operator

Other Resources

Language Reference

Community Content

Incorrect sample code

Added by:JChung2007

The ASP.NET AJAX client-side script reference should not have C#, Visual Basic, or C++ samples.

JScript sample code incorrect

Added by:M Derrick Glass

In the JScript example, the two lines here:

...
var sb = new Sys.StringBuilder(this._headTagStart);
sb.append(titleTagEnd);

should be:

var sb = new Sys.StringBuilder(headTagStart);

sb.append(titleTagStart);

Also, while the description of the expected result in the JScript sample is correct, the last statement in the Example documentation is mostly incorrect:

Finally, the code calls the toString method, passing a "|" character as a delimiter to insert between the elements of the string returned by StringBuilder.