Java String: toUppercase Method – w3resource

Java String: toUppercase() Method

Last update on August 19 2022 21:50:42 (UTC/GMT +8 hours)

public String toUpperCase(Locale locale)

The toUppercase() method is used to convert all the characters in a given string to upper case using the rules of the given
Locale. Case mapping is based on the Unicode Standard version specified by the Character class. Since case mappings are not always 1:1 char mappings, the resulting
String may be a different length than the original String.

Examples of locale-sensitive and 1:M case mappings are in the following table.

Language Code of
Locale
Lower Case
Upper Case
Description

tr (Turkish)
\u0069
\u0130
small letter i -> capital
letter I with dot above

tr (Turkish)
\u0131
\u0049
small letter dotless i ->
capital letter I

(all)
\u00df
\u0053\u0053
small letter sharp s ->
two letters: SS

(all)
Fahrvergnügen
FAHRVERGNÜGEN

Java Platform: Java SE 8

Syntax:

toUpperCase(Locale locale)

Parameters:

Name
Description
Type

locale
use the case transformation rules for this locale
String

Return Value: the String, converted to uppercase.

Return Value Type: String

Pictorial presentation of Java String toUpperCase() Method

Java String: toUpperCase() Method

Example: Java String toUppercase(Locale locale) Method

The following example shows the usage of java String() method.

public class Example {

public static void main(String[] args)
    {
        String str = "The Quick BroWnFoX jumps over the laZy Dog!";

        // Convert the above string to all lowercase.
        String upper_str = str.toUpperCase();
        System.out.println();
        // Display the two strings for comparison.
System.out.println("Original String: " + str);
System.out.println("String in uppercase: " + upper_str);
System.out.println();
    }
}

Output:

Original String: The Quick BroWnFoX jumps over the laZy Dog!                   
String in uppercase: THE QUICK BROWNFOX JUMPS OVER THE LAZY DOG!

public String toUpperCase()

Converts all of the characters in this String to upper case using the rules of the
default locale. This method is equivalent to toUpperCase(Locale.getDefault()).

Note: This method is locale sensitive, and may produce unexpected results if used for strings that are intended to be interpreted locale independently. Examples are
programming language identifiers, protocol keys, and HTML tags. For instance, “title”.toUpperCase() in a Turkish locale returns “T\u0130TLE”, where ‘\u0130’ is
the LATIN CAPITAL LETTER I WITH DOT ABOVE character. To obtain correct results for locale insensitive strings, use toUpperCase(Locale.ROOT).

Syntax:

toUpperCase()

Return Value: the String, converted to uppercase.

Example: Java String toUppercase() Method

The following example shows the usage of java String() method.

public class StringUpperCaseExample {

	public static void main(String[] args) {
		// declaring our String object
		String name = " John Gilbert ";
		System.out.println();
		// changing to lower case
		String upperCaseName = name.toUpperCase();
		System.out.println("Name in Upper Case: "+upperCaseName);
        System.out.println();
	}

}

Output:

Name in Upper Case:  JOHN GILBERT

Java Code Editor:

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