Contains Method

String.Contains Method (String)


Returns a value indicating whether a specified substring occurs within this string.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public bool Contains(
	string value


Type: System.String

The string to seek.

Return Value

Type: System.Boolean

true if the value parameter occurs within this string, or if value is the empty string (""); otherwise, false.

Exception Condition

value is null.

This method performs an ordinal (case-sensitive and culture-insensitive) comparison. The search begins at the first character position of this string and continues through the last character position.

If you are interested in the position of the substring value in the current instance, you can call the IndexOf method to get the starting position of its first occurrence, or you can call the LastIndexOf method to get the starting position of its last occurrence. The example includes a call to the IndexOf(String) method if a substring is found in a string instance.

The following example determines whether the string "fox" is a substring of a familiar quotation. If "fox" is found in the string, it also displays its starting position.

using System;

class Example
    public static void Main() 
       string s1 = "The quick brown fox jumps over the lazy dog";
       string s2 = "fox";
       bool b = s1.Contains(s2);
       Console.WriteLine("'{0}' is in the string '{1}': {2}",
                          s2, s1, b);
       if (b) {
          int index = s1.IndexOf(s2);
          if (index >= 0)
             Console.WriteLine("'{0} begins at character position {1}",
                               s2, index + 1);
// This example display the following output:
//    'fox' is in the string 'The quick brown fox jumps over the lazy dog': True
//    'fox begins at character position 17

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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