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String.Equals Method (String, String)

Determines whether two specified String objects have the same value.

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

public static bool Equals(
	string a,
	string b
)

Parameters

a
Type: System.String

The first string to compare, or null.

b
Type: System.String

The second string to compare, or null.

Return Value

Type: System.Boolean
true if the value of a is the same as the value of b; otherwise, false. If both a and b are null, the method returns true.

This method performs an ordinal (case-sensitive and culture-insensitive) comparison.

The following example demonstrates the Equals method.

// 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
*/

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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