String.ToLower Método

Origem:

String.Manipulation.cs

Origem:

String.Manipulation.cs

Origem:

String.Manipulation.cs

public:
 System::String ^ ToLower();

public string ToLower ();

member this.ToLower : unit -> string

Public Function ToLower () As String

Retornos

Uma cadeia de caracteres em letras minúsculas.

Exemplos

O exemplo a seguir converte várias cadeias de caracteres de maiúsculas e minúsculas em minúsculas.

using namespace System;
using namespace System::Collections;
int main()
{
   array<String^>^info = {"Name","Title","Age","Location","Gender"};
   Console::WriteLine( "The initial values in the array are:" );
   IEnumerator^ myEnum = info->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      String^ s = safe_cast<String^>(myEnum->Current);
      Console::WriteLine( s );
   }

   Console::WriteLine( " {0}The lowercase of these values is:", Environment::NewLine );
   IEnumerator^ myEnum1 = info->GetEnumerator();
   while ( myEnum1->MoveNext() )
   {
      String^ s = safe_cast<String^>(myEnum1->Current);
      Console::WriteLine( s->ToLower() );
   }

   Console::WriteLine( " {0}The uppercase of these values is:", Environment::NewLine );
   IEnumerator^ myEnum2 = info->GetEnumerator();
   while ( myEnum2->MoveNext() )
   {
      String^ s = safe_cast<String^>(myEnum2->Current);
      Console::WriteLine( s->ToUpper() );
   }
}
// The example displays the following output:
//       The initial values in the array are:
//       Name
//       Title
//       Age
//       Location
//       Gender
//       
//       The lowercase of these values is:
//       name
//       title
//       age
//       location
//       gender
//       
//       The uppercase of these values is:
//       NAME
//       TITLE
//       AGE
//       LOCATION
//       GENDER

using System;

public class ToLowerTest {
    public static void Main() {

        string [] info = {"Name", "Title", "Age", "Location", "Gender"};

        Console.WriteLine("The initial values in the array are:");
        foreach (string s in info)
            Console.WriteLine(s);

        Console.WriteLine("{0}The lowercase of these values is:", Environment.NewLine);

        foreach (string s in info)
            Console.WriteLine(s.ToLower());

        Console.WriteLine("{0}The uppercase of these values is:", Environment.NewLine);

        foreach (string s in info)
            Console.WriteLine(s.ToUpper());
    }
}
// The example displays the following output:
//       The initial values in the array are:
//       Name
//       Title
//       Age
//       Location
//       Gender
//
//       The lowercase of these values is:
//       name
//       title
//       age
//       location
//       gender
//
//       The uppercase of these values is:
//       NAME
//       TITLE
//       AGE
//       LOCATION
//       GENDER

open System

let info = [| "Name"; "Title"; "Age"; "Location"; "Gender" |]

printfn "The initial values in the array are:"
for s in info do
    printfn $"{s}"

printfn $"{Environment.NewLine}The lowercase of these values is:"

for s in info do
    printfn $"{s.ToLower()}"

printfn $"{Environment.NewLine}The uppercase of these values is:"

for s in info do
    printfn $"{s.ToUpper()}"
// The example displays the following output:
//       The initial values in the array are:
//       Name
//       Title
//       Age
//       Location
//       Gender
//
//       The lowercase of these values is:
//       name
//       title
//       age
//       location
//       gender
//
//       The uppercase of these values is:
//       NAME
//       TITLE
//       AGE
//       LOCATION
//       GENDER

Public Class ToLowerTest
    
    Public Shared Sub Main()
        Dim info As String() = {"Name", "Title", "Age", "Location", "Gender"}
        
        Console.WriteLine("The initial values in the array are:")

        Dim s As String
        For Each s In info
            Console.WriteLine(s)
        Next 

        Console.WriteLine("{0}The lowercase of these values is:", Environment.NewLine)

        For Each s In info
            Console.WriteLine(s.ToLower())
        Next 

        Console.WriteLine("{0}The uppercase of these values is:", Environment.NewLine)

        For Each s In  info
            Console.WriteLine(s.ToUpper())
        Next 
    End Sub 
End Class 
' The example displays the following output:
'       The initial values in the array are:
'       Name
'       Title
'       Age
'       Location
'       Gender
'       
'       The lowercase of these values is:
'       name
'       title
'       age
'       location
'       gender
'       
'       The uppercase of these values is:
'       NAME
'       TITLE
'       AGE
'       LOCATION
'       GENDER

Comentários

Esse método leva em conta as regras de uso de maiúsculas e minúsculas da cultura atual.

A operação de uso de maiúsculas e minúsculas resultante da chamada do ToLower() método leva em conta as convenções de maiúsculas e minúsculas da cultura atual. Se você precisar da versão em letras minúsculas ou maiúsculas de um identificador do sistema operacional, como um nome de arquivo, pipe nomeado ou chave do Registro, use os ToLowerInvariant métodos ou ToUpperInvariant . Isso produz o mesmo resultado em cada cultura (ao contrário do ToLower() método) e tem um desempenho mais eficiente.

Notas aos Chamadores

Conforme explicado em Práticas Recomendadas para Usar Cadeias de Caracteres, recomendamos que você evite chamar métodos de maiúsculas e minúsculas que substituam valores padrão e, em vez disso, chamem métodos que exigem que os parâmetros sejam especificados explicitamente. Para converter um caractere em letras minúsculas usando as convenções de maiúsculas e minúsculas da cultura atual, sinalize sua intenção explicitamente chamando a sobrecarga do ToLower(CultureInfo) método com um valor de CurrentCulture para seu culture parâmetro. Se você não precisar de comparação com reconhecimento linguístico, considere usar Ordinal.

Confira também

• ToLowerInvariant()
• ToUpper()
• ToUpperInvariant()

Origem:

String.Manipulation.cs

Origem:

String.Manipulation.cs

Origem:

String.Manipulation.cs

public:
 System::String ^ ToLower(System::Globalization::CultureInfo ^ culture);

public string ToLower (System.Globalization.CultureInfo? culture);

public string ToLower (System.Globalization.CultureInfo culture);

member this.ToLower : System.Globalization.CultureInfo -> string

Public Function ToLower (culture As CultureInfo) As String

Parâmetros

Retornos

O equivalente da cadeia de caracteres atual em minúsculas.

Exemplos

O exemplo a seguir converte duas cadeias de caracteres maiúsculas em caracteres minúsculos usando os Estados English-United e Turkish-Turkey culturas e compara as cadeias de caracteres minúsculas. As cadeias de caracteres maiúsculas são idênticas, exceto que para cada ocorrência da LETRA MAIÚSCULA LATINA unicode I em uma cadeia de caracteres, a outra cadeia de caracteres contém LATIN CAPITAL LETTER I WITH DOT ABOVE.

// Sample for String::ToLower(CultureInfo)
using namespace System;
using namespace System::Globalization;
void CodePoints( String^ title, String^ s )
{
   Console::Write( "{0}The code points in {1} are: {0}", Environment::NewLine, title );
   System::Collections::IEnumerator^ myEnum = s->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      UInt16 u =  safe_cast<Char>(myEnum->Current);
      Console::Write( "{0:x4} ", u );
   }

   Console::WriteLine();
}

int main()
{
   String^ str1 = "INDIGO";
   
   // str2 = str1, except each 'I' is '\u0130' (Unicode LATIN CAPITAL I WITH DOT ABOVE).
   array<Char>^temp = {L'\u0130',L'N',L'D',L'\u0130',L'G',L'O'};
   String^ str2 = gcnew String( temp );
   String^ str3;
   String^ str4;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}'", str1 );
   Console::WriteLine();
   Console::WriteLine( "str1 is {0} to str2.", ((0 == String::CompareOrdinal( str1, str2 )) ? (String^)"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( gcnew 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( gcnew 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 )) ? (String^)"equal" : "not equal") );
   CodePoints( "str3", str3 );
   CodePoints( "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
*/

// 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
*/

// Sample for String.ToLower(CultureInfo)

open System
open System.Globalization

let codePoints title s =
     printf $"{Environment.NewLine}The code points in {title} are: {Environment.NewLine}"
     for u in s do
          printf $"{u:x4} "
     printfn ""

let str1 = "INDIGO"
// str2 = str1, except each 'I' is '\u0130' (Unicode LATIN CAPITAL I WITH DOT ABOVE).
let str2 = String [| '\u0130'; 'N'; 'D'; '\u0130'; 'G'; 'O' |]

printfn $"\nstr1 = '{str1}'\n"

printfn $"""str1 is {if 0 = String.CompareOrdinal(str1, str2) then "equal" else "not equal"} to str2."""
codePoints "str1" str1
codePoints "str2" str2

// str3 is a lower case copy of str2, using English-United States culture.
printfn "\nstr3 = Lower case copy of str2 using English-United States culture."
let str3 = str2.ToLower(CultureInfo("en-US", false))

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

// Compare the code points in str3 and str4.
printfn $"""\nstr3 is {if 0 = String.CompareOrdinal(str3, str4) then "equal" else "not equal"} to str4."""
     
codePoints "str3" str3
codePoints "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
*)

' Sample for String.ToLower(CultureInfo)
Imports System.Globalization

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

   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
End Class
'
'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

Comentários

As regras de maiúsculas e minúsculas da cultura especificadas pelo culture parâmetro determinam a forma como o caso da cadeia de caracteres é alterado.

Se você passar ao ToLower(CultureInfo) método um CultureInfo objeto diferente CultureInfo.InvariantCulturede , a operação de uso de maiúsculas e minúsculas levará em conta regras específicas da cultura. Se você precisar da versão em letras minúsculas ou maiúsculas de um identificador do sistema operacional, como um nome de arquivo, pipe nomeado ou chave do Registro, use o ToLowerInvariant método ou ToUpperInvariant . Isso produz o mesmo resultado em cada cultura e tem um desempenho mais eficiente.

Confira também

• CultureInfo
• ToUpper()