String.ToUpper Method ()
.NET Framework 3.0
Returns a copy of this String converted to uppercase, using the casing rules of the current culture.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly: mscorlib (in mscorlib.dll)
This method takes into account the current culture. For more information, see the CultureInfo topic.
Security Considerations
If you need the lowercase or uppercase version of an operating system identifier, such as a file name, named pipe, or registry key, use the ToLowerInvariant or ToUpperInvariant methods.
The following code example demonstrates how you can make a String comparison case-insensitive using the ToUpper method.
unsafe { // Null terminated ASCII characters in an sbyte array String szAsciiUpper = null; sbyte[] sbArr1 = new sbyte[] { 0x41, 0x42, 0x43, 0x00 }; // Instruct the Garbage Collector not to move the memory fixed(sbyte* pAsciiUpper = sbArr1) { szAsciiUpper = new String(pAsciiUpper); } String szAsciiLower = null; sbyte[] sbArr2 = { 0x61, 0x62, 0x63, 0x00 }; // Instruct the Garbage Collector not to move the memory fixed(sbyte* pAsciiLower = sbArr2) { szAsciiLower = new String(pAsciiLower, 0, sbArr2.Length); } // Prints "ABC abc" Console.WriteLine(szAsciiUpper + " " + szAsciiLower); // Compare Strings - the result is true Console.WriteLine("The Strings are equal when capitalized ? " + (String.Compare(szAsciiUpper.ToUpper(), szAsciiLower.ToUpper())==0?"true":"false") ); // This is the effective equivalent of another Compare method, which ignores case Console.WriteLine("The Strings are equal when capitalized ? " + (String.Compare(szAsciiUpper, szAsciiLower, true)==0?"true":"false") ); }
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.