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String.ToUpper Method (CultureInfo)

Returns a copy of this string converted to uppercase, using the casing rules of the specified culture.

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

public string ToUpper(
	CultureInfo culture


Type: System.Globalization.CultureInfo
An object that supplies culture-specific casing rules.

Return Value

Type: System.String
The uppercase equivalent of the current string.


culture is null.

The casing rules of the culture specified by the culture parameter determine the way the case of the string is changed.


This method does not modify the value of the current instance. Instead, it returns a new string in which all characters in the current instance are uppercased.

The following code example converts a string of lowercase characters to two strings of uppercase characters using the English-United States and Turkish-Turkey cultures, then compares the uppercase strings. The uppercase strings are identical except that for each occurrence of the Unicode LATIN CAPITAL LETTER I in one string, the other string contains LATIN CAPITAL LETTER I WITH DOT ABOVE.

// Sample for String.ToUpper(CultureInfo)
using System;
using System.Globalization;

class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      String str1 = "indigo";
      String str2, str3;

      outputBlock.Text += "\n";
      outputBlock.Text += String.Format("str1 = '{0}'", str1) + "\n";

      outputBlock.Text += "str2 = Upper case copy of str1 using English-United States culture." + "\n";
      // str2 is an upper case copy of str1, using English-United States culture.
      str2 = str1.ToUpper(new CultureInfo("en-US"));

      // str3 is an upper case copy of str1, using Turkish-Turkey culture.
      outputBlock.Text += "str3 = Upper case copy of str1 using Turkish-Turkey culture." + "\n";
      str3 = str1.ToUpper(new CultureInfo("tr-TR"));

      // Compare the code points in str2 and str3.
      outputBlock.Text += "\n";
      outputBlock.Text += String.Format("str2 is {0} to str3.",
           ((0 == String.CompareOrdinal(str2, str3)) ? "equal" : "not equal")) + "\n";
      CodePoints(outputBlock, "str1", str1);
      CodePoints(outputBlock, "str2", str2);
      CodePoints(outputBlock, "str3", str3);

   public static void CodePoints(System.Windows.Controls.TextBlock outputBlock, String title, String s)
      outputBlock.Text += String.Format("{0}The code points in {1} are: {0}", "\n", title);
      foreach (ushort u in s)
         outputBlock.Text += String.Format("{0:x4} ", u);
      outputBlock.Text += "\n";
This example produces the following results:

str1 = 'indigo'
str2 = Upper case copy of str1 using English-United States culture.
str3 = Upper case copy of str1 using Turkish-Turkey culture.

str2 is not equal to str3.

The code points in str1 are:
0069 006e 0064 0069 0067 006f

The code points in str2 are:
0049 004e 0044 0049 0047 004f

The code points in str3 are:
0130 004e 0044 0130 0047 004f


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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