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ToUpper Method

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Returns a copy of this string converted to uppercase.

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

public string ToUpper()

Return Value

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

This method uses the casing rules of the current culture to convert each character in the current instance to its uppercase equivalent. If a character does not have an uppercase equivalent, it is included unchanged in the returned string.

NoteNote

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 converted to uppercase.

The ToUpper method is often used to convert a string to uppercase so that it can be used in a case-insensitive comparison. A better method to perform case-insensitive comparison is to call a string comparison method that has a StringComparison parameter whose value you set to StringComparison.CurrentCultureIgnoreCase for a culture-sensitive, case-insensitive comparison.

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