Java String toUpperCase()

The syntax of the string toUpperCase() method is:

 string.toUpperCase()

toUpperCase() Parameters

• doesn't take any parameters

toUpperCase() Return Value

• returns a string with all lower case letters converted to upper case

Example: Java toUpperCase()

 class Main { public static void main(String[] args) { String str1 = "Learn Java"; String str2 = "Java123"; // convert to upper case letters System.out.println(str1.toUpperCase()); // "LEARN JAVA" System.out.println(str2.toUpperCase()); // "JAVA123" } }

As you can see from the above example, toUpperCase() converts all lower case letters to upper case letters.

toUpperCase() With Locale Parameter

The toUpperCase() method can also take a locale as an argument. This allows you to convert all characters in a string to upper case using the given Locale (such as: Turkish, Lithuanian etc.) rules.

Its syntax is:

 string.toUpperCase(Locale locale)

If you do not pass the locale parameter, the default locale, Locale.getDefault(), is used.

To learn more, visit Java toUpperCase() With Locale.

To convert all characters in a string to lower case letters, use the Java String toLowerCase() method.