String.Equals
Method
Definition
Overloads
| Equals(Object) |
Determines whether this instance and a specified object, which must also be a String object, have the same value. |
| Equals(String) |
Determines whether this instance and another specified String object have the same value. |
| Equals(String, String) |
Determines whether two specified String objects have the same value. |
| Equals(String, StringComparison) |
Determines whether this string and a specified String object have the same value. A parameter specifies the culture, case, and sort rules used in the comparison. |
| Equals(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. |
Equals(Object)
Determines whether this instance and a specified object, which must also be a String object, have the same value.
public override bool Equals (object obj);
- obj
- Object
The string to compare to this instance.
true if obj is a String and its value is the same as this instance; otherwise, false. If obj is null, the method returns false.
Examples
The following example demonstrates the Equals method.
// Sample for String::Equals(Object)
// String::Equals(String)
// String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
StringBuilder^ sb = gcnew StringBuilder( "abcd" );
String^ str1 = "abcd";
String^ str2 = nullptr;
Object^ o2 = nullptr;
Console::WriteLine();
Console::WriteLine( " * The value of String str1 is '{0}'.", str1 );
Console::WriteLine( " * The value of StringBuilder sb is '{0}'.", sb );
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
*/
// 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
*/
' Sample for String.Equals(Object)
' String.Equals(String)
' String.Equals(String, String)
Imports System
Imports System.Text
Class Sample
Public Shared Sub Main()
Dim sb As New StringBuilder("abcd")
Dim str1 As [String] = "abcd"
Dim str2 As [String] = Nothing
Dim o2 As [Object] = Nothing
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))
End Sub 'Main
End Class 'Sample
'
'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
'
Remarks
This method performs an ordinal (case-sensitive and culture-insensitive) comparison.
Equals(String)
Determines whether this instance and another specified String object have the same value.
public bool Equals (string value);
- value
- String
The string to compare to this instance.
true if the value of the value parameter is the same as the value of this instance; otherwise, false. If value is null, the method returns false.
Examples
The following example demonstrates the Equals method.It compares the title-cased word "File" with an equivalent word, its lowercase equivalent, its uppercase equivalent, and a word that contains LATIN SMALL LETTER DOTLESS I (U+0131) instead of LATIN SMALL LETTER I (U+0069). Because the Equals(String) method performs an ordinal comparison, only the comparison with an identical word returns true.
using System;
public class Example
{
public static void Main()
{
Console.OutputEncoding = System.Text.Encoding.UTF8;
string word = "File";
string[] others = { word.ToLower(), word, word.ToUpper(), "fıle" };
foreach (string other in others)
{
if (word.Equals(other))
Console.WriteLine("{0} = {1}", word, other);
else
Console.WriteLine("{0} {1} {2}", word, '\u2260', other);
}
}
}
// The example displays the following output:
// File ≠ file
// File = File
// File ≠ FILE
// File ≠ fıle
Module Example
Public Sub Main()
Console.OutputEncoding = System.Text.Encoding.UTF8
Dim word As String = "File"
Dim others() As String = { word.ToLower(), word, word.ToUpper(), _
"fıle" }
For Each other As String In others
If word.Equals(other) Then
Console.WriteLine("{0} = {1}", word, other)
Else
Console.WriteLine("{0} {1} {2}", word, ChrW(&H2260), other)
End If
Next
End Sub
End Module
' The example displays the following output:
' File ≠ file
' File = File
' File ≠ FILE
' File ≠ fıle
Remarks
This method performs an ordinal (case-sensitive and culture-insensitive) comparison.
Equals(String, String)
Determines whether two specified String objects have the same value.
public static bool Equals (string a, string b);
- a
- String
The first string to compare, or null.
- b
- String
The second string to compare, or null.
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.
Examples
The following example demonstrates the Equals method.
// Sample for String::Equals(Object)
// String::Equals(String)
// String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
StringBuilder^ sb = gcnew StringBuilder( "abcd" );
String^ str1 = "abcd";
String^ str2 = nullptr;
Object^ o2 = nullptr;
Console::WriteLine();
Console::WriteLine( " * The value of String str1 is '{0}'.", str1 );
Console::WriteLine( " * The value of StringBuilder sb is '{0}'.", sb );
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
*/
// 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
*/
' Sample for String.Equals(Object)
' String.Equals(String)
' String.Equals(String, String)
Imports System
Imports System.Text
Class Sample
Public Shared Sub Main()
Dim sb As New StringBuilder("abcd")
Dim str1 As [String] = "abcd"
Dim str2 As [String] = Nothing
Dim o2 As [Object] = Nothing
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))
End Sub 'Main
End Class 'Sample
'
'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
'
Remarks
This method performs an ordinal (case-sensitive and culture-insensitive) comparison.
Equals(String, StringComparison)
Determines whether this string and a specified String object have the same value. A parameter specifies the culture, case, and sort rules used in the comparison.
public bool Equals (string value, StringComparison comparisonType);
- value
- String
The string to compare to this instance.
- comparisonType
- StringComparison
One of the enumeration values that specifies how the strings will be compared.
true if the value of the value parameter is the same as this string; otherwise, false.
comparisonType is not a StringComparison value.
Examples
The following example creates a string array that consists of an uppercase "I", a lowercase "i", and a dotless "ı". It then calls the Equals(String, StringComparison) method to compare them by using each possible StringComparison enumeration value.
using System;
class Sample
{
public static void Main()
{
// Define a string array with the following three "I" characters:
// U+0069, U+0131, and U+0049.
string[] threeIs = { "i", "ı", "I" };
// Define Type object representing StringComparison type.
Type scType = typeof(StringComparison);
// Show the current culture (for culture-sensitive string comparisons).
Console.WriteLine("The current culture is {0}.\n",
System.Globalization.CultureInfo.CurrentCulture.Name);
// Perform comparisons using each StringComparison member.
foreach (string scName in Enum.GetNames(scType))
{
StringComparison sc = (StringComparison) Enum.Parse(scType, scName);
Console.WriteLine("Comparisons using {0}:", sc);
// Compare each character in character array.
for (int ctr = 0; ctr <= 1; ctr++)
{
string instanceChar = threeIs[ctr];
for (int innerCtr = ctr + 1; innerCtr <= threeIs.GetUpperBound(0); innerCtr++)
{
string otherChar = threeIs[innerCtr];
Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}",
instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"),
otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"),
instanceChar.Equals(otherChar, sc));
}
Console.WriteLine();
}
}
}
}
// The example displays the following output:
// The current culture is en-US.
//
// Comparisons using CurrentCulture:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): False
//
// i (U+0131) = I (U+0049): False
//
// Comparisons using CurrentCultureIgnoreCase:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): True
//
// i (U+0131) = I (U+0049): False
//
// Comparisons using InvariantCulture:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): False
//
// i (U+0131) = I (U+0049): False
//
// Comparisons using InvariantCultureIgnoreCase:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): True
//
// i (U+0131) = I (U+0049): False
//
// Comparisons using Ordinal:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): False
//
// i (U+0131) = I (U+0049): False
//
// Comparisons using OrdinalIgnoreCase:
// i (U+0069) = i (U+0131): False
// i (U+0069) = I (U+0049): True
//
// i (U+0131) = I (U+0049): False
Class Sample
Public Shared Sub Main()
' Define a string array with the following three "I" characters:
' U+0069, U+0131, and U+0049.
Dim threeIs() As String = { "i", "ı", "I" }
' Define Type object representing StringComparison type.
Dim scType As Type = GetType(StringComparison)
' Show the current culture (for culture-sensitive string comparisons).
Console.WriteLine("The current culture is {0}." & vbCrLf, _
System.Globalization.CultureInfo.CurrentCulture.Name)
' Perform comparisons using each StringComparison member.
For Each scName As String In [Enum].GetNames(scType)
Dim sc As StringComparison = [Enum].Parse(scType, scName)
Console.WriteLine("Comparisons using {0}:", sc)
' Compare each character in character array.
For ctr As Integer = 0 To 1
Dim instanceChar As String = threeIs(ctr)
For innerCtr As Integer = ctr + 1 To threeIs.GetUpperBound(0)
Dim otherChar As STring = threeIs(innerCtr)
Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", _
instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), _
otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), _
instanceChar.Equals(otherChar, sc))
Next
Console.WriteLine()
Next
Next
End Sub
End Class
' The example displays the following output:
' The current culture is en-US.
'
' Comparisons using CurrentCulture:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): False
'
' i (U+0131) = I (U+0049): False
'
' Comparisons using CurrentCultureIgnoreCase:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): True
'
' i (U+0131) = I (U+0049): False
'
' Comparisons using InvariantCulture:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): False
'
' i (U+0131) = I (U+0049): False
'
' Comparisons using InvariantCultureIgnoreCase:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): True
'
' i (U+0131) = I (U+0049): False
'
' Comparisons using Ordinal:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): False
'
' i (U+0131) = I (U+0049): False
'
' Comparisons using OrdinalIgnoreCase:
' i (U+0069) = i (U+0131): False
' i (U+0069) = I (U+0049): True
'
' i (U+0131) = I (U+0049): False
The following example compares four sets of words by using each member of the StringComparison enumeration. The comparisons use the conventions of the English (United States) and Sami (Upper Sweden) cultures. Note that the strings "encyclopædia" and "encyclopedia" are considered equivalent in the en-US culture but not in the Sami (Northern Sweden) culture.
using System;
using System.Globalization;
using System.Threading;
public class Example
{
public static void Main()
{
String[] cultureNames = { "en-US", "se-SE" };
String[] strings1 = { "case", "encyclopædia",
"encyclopædia", "Archæology" };
String[] strings2 = { "Case", "encyclopaedia",
"encyclopedia" , "ARCHÆOLOGY" };
StringComparison[] comparisons = (StringComparison[]) Enum.GetValues(typeof(StringComparison));
foreach (var cultureName in cultureNames) {
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName);
Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name);
for (int ctr = 0; ctr <= strings1.GetUpperBound(0); ctr++) {
foreach (var comparison in comparisons)
Console.WriteLine(" {0} = {1} ({2}): {3}", strings1[ctr],
strings2[ctr], comparison,
strings1[ctr].Equals(strings2[ctr], comparison));
Console.WriteLine();
}
Console.WriteLine();
}
}
}
// The example displays the following output:
// Current Culture: en-US
// case = Case (CurrentCulture): False
// case = Case (CurrentCultureIgnoreCase): True
// case = Case (InvariantCulture): False
// case = Case (InvariantCultureIgnoreCase): True
// case = Case (Ordinal): False
// case = Case (OrdinalIgnoreCase): True
//
// encyclopædia = encyclopaedia (CurrentCulture): True
// encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
// encyclopædia = encyclopaedia (InvariantCulture): True
// encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
// encyclopædia = encyclopaedia (Ordinal): False
// encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//
// encyclopædia = encyclopedia (CurrentCulture): False
// encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopedia (InvariantCulture): False
// encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
// encyclopædia = encyclopedia (Ordinal): False
// encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//
// Archæology = ARCHÆOLOGY (CurrentCulture): False
// Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (InvariantCulture): False
// Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (Ordinal): False
// Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
//
//
// Current Culture: se-SE
// case = Case (CurrentCulture): False
// case = Case (CurrentCultureIgnoreCase): True
// case = Case (InvariantCulture): False
// case = Case (InvariantCultureIgnoreCase): True
// case = Case (Ordinal): False
// case = Case (OrdinalIgnoreCase): True
//
// encyclopædia = encyclopaedia (CurrentCulture): False
// encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopaedia (InvariantCulture): True
// encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
// encyclopædia = encyclopaedia (Ordinal): False
// encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//
// encyclopædia = encyclopedia (CurrentCulture): False
// encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopedia (InvariantCulture): False
// encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
// encyclopædia = encyclopedia (Ordinal): False
// encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//
// Archæology = ARCHÆOLOGY (CurrentCulture): False
// Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (InvariantCulture): False
// Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (Ordinal): False
// Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
Imports System.Globalization
Imports System.Threading
Module Example
Public Sub Main()
Dim cultureNames() As String = { "en-US", "se-SE" }
Dim strings1() As String = { "case", "encyclopædia",
"encyclopædia", "Archæology" }
Dim strings2() As String = { "Case", "encyclopaedia",
"encyclopedia" , "ARCHÆOLOGY" }
Dim comparisons() As StringComparison = CType([Enum].GetValues(GetType(StringComparison)),
StringComparison())
For Each cultureName In cultureNames
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName)
Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name)
For ctr As Integer = 0 To strings1.GetUpperBound(0)
For Each comparison In comparisons
Console.WriteLine(" {0} = {1} ({2}): {3}", strings1(ctr),
strings2(ctr), comparison,
strings1(ctr).Equals(strings2(ctr), comparison))
Next
Console.WriteLine()
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' Current Culture: en-US
' case = Case (CurrentCulture): False
' case = Case (CurrentCultureIgnoreCase): True
' case = Case (InvariantCulture): False
' case = Case (InvariantCultureIgnoreCase): True
' case = Case (Ordinal): False
' case = Case (OrdinalIgnoreCase): True
'
' encyclopædia = encyclopaedia (CurrentCulture): True
' encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
' encyclopædia = encyclopaedia (InvariantCulture): True
' encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
' encyclopædia = encyclopaedia (Ordinal): False
' encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'
' encyclopædia = encyclopedia (CurrentCulture): False
' encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopedia (InvariantCulture): False
' encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
' encyclopædia = encyclopedia (Ordinal): False
' encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'
' Archæology = ARCHÆOLOGY (CurrentCulture): False
' Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (InvariantCulture): False
' Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (Ordinal): False
' Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
'
'
' Current Culture: se-SE
' case = Case (CurrentCulture): False
' case = Case (CurrentCultureIgnoreCase): True
' case = Case (InvariantCulture): False
' case = Case (InvariantCultureIgnoreCase): True
' case = Case (Ordinal): False
' case = Case (OrdinalIgnoreCase): True
'
' encyclopædia = encyclopaedia (CurrentCulture): False
' encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopaedia (InvariantCulture): True
' encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
' encyclopædia = encyclopaedia (Ordinal): False
' encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'
' encyclopædia = encyclopedia (CurrentCulture): False
' encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopedia (InvariantCulture): False
' encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
' encyclopædia = encyclopedia (Ordinal): False
' encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'
' Archæology = ARCHÆOLOGY (CurrentCulture): False
' Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (InvariantCulture): False
' Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (Ordinal): False
' Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
Remarks
The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the two strings being compared, or use word or ordinal sort rules.
Equals(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.
public static bool Equals (string a, string b, StringComparison comparisonType);
- a
- String
The first string to compare, or null.
- b
- String
The second string to compare, or null.
- comparisonType
- StringComparison
One of the enumeration values that specifies the rules for the comparison.
true if the value of the a parameter is equal to the value of the b parameter; otherwise, false.
comparisonType is not a StringComparison value.
Examples
The following example compares four sets of words by using each member of the StringComparison enumeration. The comparisons use the conventions of the English (United States) and Sami (Upper Sweden) cultures. Note that the strings "encyclopædia" and "encyclopedia" are considered equivalent in the en-US culture but not in the Sami (Northern Sweden) culture.
using System;
using System.Globalization;
using System.Threading;
public class Example
{
public static void Main()
{
String[] cultureNames = { "en-US", "se-SE" };
String[] strings1 = { "case", "encyclopædia",
"encyclopædia", "Archæology" };
String[] strings2 = { "Case", "encyclopaedia",
"encyclopedia" , "ARCHÆOLOGY" };
StringComparison[] comparisons = (StringComparison[]) Enum.GetValues(typeof(StringComparison));
foreach (var cultureName in cultureNames) {
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName);
Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name);
for (int ctr = 0; ctr <= strings1.GetUpperBound(0); ctr++) {
foreach (var comparison in comparisons)
Console.WriteLine(" {0} = {1} ({2}): {3}", strings1[ctr],
strings2[ctr], comparison,
String.Equals(strings1[ctr], strings2[ctr], comparison));
Console.WriteLine();
}
Console.WriteLine();
}
}
}
// The example displays the following output:
// Current Culture: en-US
// case = Case (CurrentCulture): False
// case = Case (CurrentCultureIgnoreCase): True
// case = Case (InvariantCulture): False
// case = Case (InvariantCultureIgnoreCase): True
// case = Case (Ordinal): False
// case = Case (OrdinalIgnoreCase): True
//
// encyclopædia = encyclopaedia (CurrentCulture): True
// encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
// encyclopædia = encyclopaedia (InvariantCulture): True
// encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
// encyclopædia = encyclopaedia (Ordinal): False
// encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//
// encyclopædia = encyclopedia (CurrentCulture): False
// encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopedia (InvariantCulture): False
// encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
// encyclopædia = encyclopedia (Ordinal): False
// encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//
// Archæology = ARCHÆOLOGY (CurrentCulture): False
// Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (InvariantCulture): False
// Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (Ordinal): False
// Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
//
//
// Current Culture: se-SE
// case = Case (CurrentCulture): False
// case = Case (CurrentCultureIgnoreCase): True
// case = Case (InvariantCulture): False
// case = Case (InvariantCultureIgnoreCase): True
// case = Case (Ordinal): False
// case = Case (OrdinalIgnoreCase): True
//
// encyclopædia = encyclopaedia (CurrentCulture): False
// encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopaedia (InvariantCulture): True
// encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
// encyclopædia = encyclopaedia (Ordinal): False
// encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//
// encyclopædia = encyclopedia (CurrentCulture): False
// encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
// encyclopædia = encyclopedia (InvariantCulture): False
// encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
// encyclopædia = encyclopedia (Ordinal): False
// encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//
// Archæology = ARCHÆOLOGY (CurrentCulture): False
// Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (InvariantCulture): False
// Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
// Archæology = ARCHÆOLOGY (Ordinal): False
// Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
Imports System.Globalization
Imports System.Threading
Module Example
Public Sub Main()
Dim cultureNames() As String = { "en-US", "se-SE" }
Dim strings1() As String = { "case", "encyclopædia",
"encyclopædia", "Archæology" }
Dim strings2() As String = { "Case", "encyclopaedia",
"encyclopedia" , "ARCHÆOLOGY" }
Dim comparisons() As StringComparison = CType([Enum].GetValues(GetType(StringComparison)),
StringComparison())
For Each cultureName In cultureNames
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName)
Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name)
For ctr As Integer = 0 To strings1.GetUpperBound(0)
For Each comparison In comparisons
Console.WriteLine(" {0} = {1} ({2}): {3}", strings1(ctr),
strings2(ctr), comparison,
String.Equals(strings1(ctr), strings2(ctr), comparison))
Next
Console.WriteLine()
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' Current Culture: en-US
' case = Case (CurrentCulture): False
' case = Case (CurrentCultureIgnoreCase): True
' case = Case (InvariantCulture): False
' case = Case (InvariantCultureIgnoreCase): True
' case = Case (Ordinal): False
' case = Case (OrdinalIgnoreCase): True
'
' encyclopædia = encyclopaedia (CurrentCulture): True
' encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
' encyclopædia = encyclopaedia (InvariantCulture): True
' encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
' encyclopædia = encyclopaedia (Ordinal): False
' encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'
' encyclopædia = encyclopedia (CurrentCulture): False
' encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopedia (InvariantCulture): False
' encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
' encyclopædia = encyclopedia (Ordinal): False
' encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'
' Archæology = ARCHÆOLOGY (CurrentCulture): False
' Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (InvariantCulture): False
' Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (Ordinal): False
' Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
'
'
' Current Culture: se-SE
' case = Case (CurrentCulture): False
' case = Case (CurrentCultureIgnoreCase): True
' case = Case (InvariantCulture): False
' case = Case (InvariantCultureIgnoreCase): True
' case = Case (Ordinal): False
' case = Case (OrdinalIgnoreCase): True
'
' encyclopædia = encyclopaedia (CurrentCulture): False
' encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopaedia (InvariantCulture): True
' encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
' encyclopædia = encyclopaedia (Ordinal): False
' encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'
' encyclopædia = encyclopedia (CurrentCulture): False
' encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
' encyclopædia = encyclopedia (InvariantCulture): False
' encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
' encyclopædia = encyclopedia (Ordinal): False
' encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'
' Archæology = ARCHÆOLOGY (CurrentCulture): False
' Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (InvariantCulture): False
' Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
' Archæology = ARCHÆOLOGY (Ordinal): False
' Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
Remarks
The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the two strings being compared, or use word or ordinal sort rules.