String.Equals Method (String, String, StringComparison)
Determines whether two specified String objects have the same value. A parameter specifies the culture, case, and sort rules used in the comparison.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Parameters
- a
- Type: System.String
The first string to compare, or null.
- b
- Type: System.String
The second string to compare, or null.
- comparisonType
- Type: System.StringComparison
One of the enumeration values that specifies the rules for the comparison.
Return Value
Type: System.Booleantrue if the value of the a parameter is equal to the value of the b parameter; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentException | comparisonType is not a StringComparison value. |
The following example uses three versions of the Equals method to determine whether a String object and a StringBuilder object are equal.
// Sample for String.Equals(Object) // String.Equals(String) // String.Equals(String, String) using System; using System.Text; class Sample { public static void Main() { StringBuilder sb = new StringBuilder("abcd"); String str1 = "abcd"; String str2 = null; Object o2 = null; Console.WriteLine(); Console.WriteLine(" * The value of String str1 is '{0}'.", str1); Console.WriteLine(" * The value of StringBuilder sb is '{0}'.", sb.ToString()); Console.WriteLine(); Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String."); Console.WriteLine(" Is str1 equal to sb?: {0}", str1.Equals(sb)); Console.WriteLine(); Console.WriteLine("1b) String.Equals(Object). Object is a String."); str2 = sb.ToString(); o2 = str2; Console.WriteLine(" * The value of Object o2 is '{0}'.", o2); Console.WriteLine(" Is str1 equal to o2?: {0}", str1.Equals(o2)); Console.WriteLine(); Console.WriteLine(" 2) String.Equals(String)"); Console.WriteLine(" * The value of String str2 is '{0}'.", str2); Console.WriteLine(" Is str1 equal to str2?: {0}", str1.Equals(str2)); Console.WriteLine(); Console.WriteLine(" 3) String.Equals(String, String)"); Console.WriteLine(" Is str1 equal to str2?: {0}", String.Equals(str1, str2)); } } /* This example produces the following results: * The value of String str1 is 'abcd'. * The value of StringBuilder sb is 'abcd'. 1a) String.Equals(Object). Object is a StringBuilder, not a String. Is str1 equal to sb?: False 1b) String.Equals(Object). Object is a String. * The value of Object o2 is 'abcd'. Is str1 equal to o2?: True 2) String.Equals(String) * The value of String str2 is 'abcd'. Is str1 equal to str2?: True 3) String.Equals(String, String) Is str1 equal to str2?: True */
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
