Updated: October 2008
Retrieves a substring from this instance. The substring starts at a specified character position and has a specified length.
Namespace:
System
Assembly:
mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
Public Function Substring ( _
startIndex As Integer, _
length As Integer _
) As String
Dim instance As String
Dim startIndex As Integer
Dim length As Integer
Dim returnValue As String
returnValue = instance.Substring(startIndex, _
length)
public string Substring(
int startIndex,
int length
)
public:
String^ Substring(
int startIndex,
int length
)
public function Substring(
startIndex : int,
length : int
) : String
Parameters
- startIndex
- Type: System..::.Int32
The zero-based starting character position of a substring in this instance.
- length
- Type: System..::.Int32
The number of characters in the substring.
Return Value
Type:
System..::.StringA String equivalent to the substring of length length that begins at startIndex in this instance, or Empty if startIndex is equal to the length of this instance and length is zero.
| Exception | Condition |
|---|
| ArgumentOutOfRangeException |
startIndex plus length indicates a position not within this instance. -or-
startIndex or length is less than zero. |
startIndex is zero-based.
Note: |
|---|
This method does not modify the value of the current instance. Instead, it returns a new string with length characters starting from the startIndex character position in the current instance. |
The following example uses the Substring method in three cases to isolate substrings within a string. In two cases the substrings are used in comparisons, and in the third case an exception is thrown because invalid parameters are specified.
Dim myString As String = "abc"
Dim test1 As Boolean = myString.Substring(2, 1).Equals("c") ' This is true.
Console.WriteLine(test1)
Dim test2 As Boolean = String.IsNullOrEmpty(myString.Substring(3, 0)) ' This is true.
Console.WriteLine(test2)
Try
Dim str3 As String = myString.Substring(3, 1) ' This throws ArgumentOutOfRangeException.
Console.WriteLine(str3)
Catch e As ArgumentOutOfRangeException
Console.WriteLIne(e.Message)
End Try
String myString = "abc";
bool test1 = myString.Substring(2, 1).Equals("c"); // This is true.
Console.WriteLine(test1);
bool test2 = String.IsNullOrEmpty(myString.Substring(3, 0)); // This is true.
Console.WriteLine(test2);
try {
string str3 = myString.Substring(3, 1); // This throws ArgumentOutOfRangeException.
Console.WriteLine(str3);
}
catch (ArgumentOutOfRangeException e) {
Console.WriteLine(e.Message);
}
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference
Date | History | Reason |
|---|
October 2008
| Added a note that the method returns a new String object. |
Customer feedback.
|