How to: Search for a String in an Array of Strings

This example calls the IndexOf method on an array of strings to report the string number and index of the first occurrence of a substring.

Example

string[] strArray = {"ABCDEFG", "HIJKLMNOP"};
string findThisString = "JKL";
int strNumber;
int strIndex = 0;
for (strNumber = 0; strNumber < strArray.Length; strNumber+)
{
    strIndex = strArray[strNumber].IndexOf(findThisString);
    if (strIndex >= 0)
        break;
}
System.Console.WriteLine("String number: {0}\nString index: {1}",
    strNumber, strIndex);

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.

See Also

Concepts

C# Language Primer

Other Resources

Visual C# Express