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String.ToLower Method

Returns a copy of this String in lowercase.

Overload List

Returns a copy of this String in lowercase, using the casing rules of the current culture.

Supported by the .NET Compact Framework.

[Visual Basic] Overloads Public Function ToLower() As String
[C#] public string ToLower();
[C++] public: String* ToLower();
[JScript] public function ToLower() : String;

Returns a copy of this String in lowercase, using the casing rules of the specified culture.

Supported by the .NET Compact Framework.

[Visual Basic] Overloads Public Function ToLower(CultureInfo) As String
[C#] public string ToLower(CultureInfo);
[C++] public: String* ToLower(CultureInfo*);
[JScript] public function ToLower(CultureInfo) : String;

Example

[Visual Basic, C#, C++] Note   This example shows how to use one of the overloaded versions of ToLower. For other examples that might be available, see the individual overload topics.
[Visual Basic] 
' Sample for String.ToLower(CultureInfo)
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic

Class Sample
   Public Shared Sub Main()
      Dim str1 As [String] = "INDIGO"
      ' str2 = str1, except each 'I' is '\u0130' (Unicode LATIN CAPITAL I WITH DOT ABOVE).
      Dim str2 As New [String](New [Char]() {ChrW(&H0130), "N"c, "D"c, ChrW(&H0130), "G"c, "O"c})
      Dim str3, str4 As [String]

      Console.WriteLine()
      Console.WriteLine("str1 = '{0}'", str1)

      Console.WriteLine()
      Console.WriteLine("str1 is {0} to str2.", _
                         IIf(0 = [String].CompareOrdinal(str1, str2), "equal", "not equal"))
      CodePoints("str1", str1)
      CodePoints("str2", str2)

      Console.WriteLine()
      ' str3 is a lower case copy of str2, using English-United States culture.
      Console.WriteLine("str3 = Lower case copy of str2 using English-United States culture.")
      str3 = str2.ToLower(New CultureInfo("en-US", False))

      ' str4 is a lower case copy of str2, using Turkish-Turkey culture.
      Console.WriteLine("str4 = Lower case copy of str2 using Turkish-Turkey culture.")
      str4 = str2.ToLower(New CultureInfo("tr-TR", False))

      ' Compare the code points in str3 and str4.
      Console.WriteLine()
      Console.WriteLine("str3 is {0} to str4.", _
                         IIf(0 = [String].CompareOrdinal(str3, str4), "equal", "not equal"))
      CodePoints("str3", str3)
      CodePoints("str4", str4)
   End Sub 'Main

   Public Shared Sub CodePoints(title As [String], s As [String])
      Console.Write("{0}The code points in {1} are: {0}", Environment.NewLine, title)
      Dim c As Char
      For Each c In  s
         Console.Write("{0:x4} ", AscW(c))
      Next c
      Console.WriteLine()
   End Sub 'CodePoints
End Class 'Sample
'
'str1 = 'INDIGO'
'
'str1 is not equal to str2.
'
'The code points in str1 are:
'0049 004e 0044 0049 0047 004f
'
'The code points in str2 are:
'0130 004e 0044 0130 0047 004f
'
'str3 = Lower case copy of str2 using English-United States culture.
'str4 = Lower case copy of str2 using Turkish-Turkey culture.
'
'str3 is equal to str4.
'
'The code points in str3 are:
'0069 006e 0064 0069 0067 006f
'
'The code points in str4 are:
'0069 006e 0064 0069 0067 006f

[C#] 
// Sample for String.ToLower(CultureInfo)

using System;
using System.Globalization;

class Sample 
{
    public static void Main() 
    {
    String str1 = "INDIGO";
    // str2 = str1, except each 'I' is '\u0130' (Unicode LATIN CAPITAL I WITH DOT ABOVE).
    String str2 = new String(new Char[] {'\u0130', 'N', 'D', '\u0130', 'G', 'O'});
    String str3, str4;

    Console.WriteLine();
    Console.WriteLine("str1 = '{0}'", str1);

    Console.WriteLine();
    Console.WriteLine("str1 is {0} to str2.", 
         ((0 == String.CompareOrdinal(str1, str2)) ? "equal" : "not equal"));
    CodePoints("str1", str1);
    CodePoints("str2", str2);

    Console.WriteLine();
    // str3 is a lower case copy of str2, using English-United States culture.
    Console.WriteLine("str3 = Lower case copy of str2 using English-United States culture.");
    str3 = str2.ToLower(new CultureInfo("en-US", false));

    // str4 is a lower case copy of str2, using Turkish-Turkey culture.
    Console.WriteLine("str4 = Lower case copy of str2 using Turkish-Turkey culture.");
    str4 = str2.ToLower(new CultureInfo("tr-TR", false));

    // Compare the code points in str3 and str4.
    Console.WriteLine();
    Console.WriteLine("str3 is {0} to str4.", 
         ((0 == String.CompareOrdinal(str3, str4)) ? "equal" : "not equal"));
    CodePoints("str3", str3);
    CodePoints("str4", str4);
    }

    public static void CodePoints(String title, String s)
    {
    Console.Write("{0}The code points in {1} are: {0}", Environment.NewLine, title);
    foreach (ushort u in s)
      Console.Write("{0:x4} ", u);
    Console.WriteLine();
    }
}
/*
This example produces the following results:

str1 = 'INDIGO'

str1 is not equal to str2.

The code points in str1 are:
0049 004e 0044 0049 0047 004f

The code points in str2 are:
0130 004e 0044 0130 0047 004f

str3 = Lower case copy of str2 using English-United States culture.
str4 = Lower case copy of str2 using Turkish-Turkey culture.

str3 is equal to str4.

The code points in str3 are:
0069 006e 0064 0069 0067 006f

The code points in str4 are:
0069 006e 0064 0069 0067 006f
*/

[C++] 
// Sample for String::ToLower(CultureInfo)

#using <mscorlib.dll>

using namespace System;
using namespace System::Globalization;

void CodePoints(String* title, String* s) {
   Console::Write(S"{0}The code points in {1} are: {0}", Environment::NewLine, title);
   System::Collections::IEnumerator* myEnum = s->GetEnumerator();
   while (myEnum->MoveNext()) {
      UInt16 u = *__try_cast<Char*>(myEnum->Current);
      Console::Write(S"{0:x4} ", __box(u));
   }
   Console::WriteLine();
}
int main() {
   String*  str1 = S"INDIGO";
   // str2 = str1, except each 'I' is '\u0130' (Unicode LATIN CAPITAL I WITH DOT ABOVE).
   Char temp[] = {L'\u0130', L'N', L'D', L'\u0130', L'G', L'O'};
   String* str2 = new String(temp);
   String* str3, *str4;

   Console::WriteLine();
   Console::WriteLine(S"str1 = '{0}'", str1);

   Console::WriteLine();
   Console::WriteLine(S"str1 is {0} to str2.",
      ((0 == String::CompareOrdinal(str1, str2)) ? S"equal" : S"not equal"));
   CodePoints(S"str1", str1);
   CodePoints(S"str2", str2);

   Console::WriteLine();
   // str3 is a lower case copy of str2, using English-United States culture.
   Console::WriteLine(S"str3 = Lower case copy of str2 using English-United States culture.");
   str3 = str2->ToLower(new CultureInfo(S"en-US", false));

   // str4 is a lower case copy of str2, using Turkish-Turkey culture.
   Console::WriteLine(S"str4 = Lower case copy of str2 using Turkish-Turkey culture.");
   str4 = str2->ToLower(new CultureInfo(S"tr-TR", false));

   // Compare the code points in str3 and str4.
   Console::WriteLine();
   Console::WriteLine(S"str3 is {0} to str4.",
      ((0 == String::CompareOrdinal(str3, str4)) ? S"equal" : S"not equal"));
   CodePoints(S"str3", str3);
   CodePoints(S"str4", str4);
}

/*
This example produces the following results:

str1 = 'INDIGO'

str1 is not equal to str2.

The code points in str1 are:
0049 004e 0044 0049 0047 004f

The code points in str2 are:
0130 004e 0044 0130 0047 004f

str3 = Lower case copy of str2 using English-United States culture.
str4 = Lower case copy of str2 using Turkish-Turkey culture.

str3 is equal to str4.

The code points in str3 are:
0069 006e 0064 0069 0067 006f

The code points in str4 are:
0069 006e 0064 0069 0067 006f
*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

See Also

String Class | String Members | System Namespace

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