How to: Search Within a String
This example calls the IndexOf method on a String object to report the index of the first occurrence of a substring.
Example
string searchWithinThis = "ABCDEFGHIJKLMNOP";
string searchForThis = "DEF";
int firstCharacter = searchWithinThis.IndexOf(searchForThis);
System.Console.WriteLine("First occurrence: {0}", firstCharacter);
Compiling the Code
Copy the code and paste it into the Main method of a console application.
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.
If you want more control over possible exceptions, enclose the string search in a try-catch statement.