How to: Search Within a String (Visual Basic)
This example calls the IndexOf method on a String object to report the index of the first occurrence of a substring.
Example
Dim SearchWithinThis As String = "ABCDEFGHIJKLMNOP"
Dim SearchForThis As String = "DEF"
Dim FirstCharacter As Integer = SearchWithinThis.IndexOf(SearchForThis)
Compiling the Code
This example requires:
- An Imports statement specifying the System namespace. For more information, see Imports Statement (.NET Namespace and Type).
Robust Programming
The IndexOf method reports the location of the first character of the first occurrence of the substring. The index is 0-based, which means the first character of a string has an index of 0.
If IndexOf does not find the substring, it returns -1.
The IndexOf method is case-sensitive and uses the current culture.
For optimal error control, you might want to enclose the string search in the Try block of a Try...Catch...Finally Statement (Visual Basic) construction.
See Also
Reference
Try...Catch...Finally Statement (Visual Basic)