Windows Dev Center

Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

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

Show:
© 2015 Microsoft