How to convert a list of strings to uppercase in Java

To convert a list of strings to uppercase in Java, you can use the List.replaceAll() method. The List.replaceAll() method replaces each list element with the result of applying the operator to that element.

// Declare a list
List<String> list = Arrays.asList("a", "b", "c");

// Uppercase the list
list.replaceAll(String::toUpperCase);

// Print list elements
list.forEach(System.out::println);

// A
// B
// C

Alternatively, you can use the Streams API map() method to transfer a list of strings to uppercase in Java:

// Declare a list
List<String> list = Arrays.asList("a", "b", "c");

// Uppercase the list
list = list.stream().map(String::toUpperCase).collect(Collectors.toList());

// Print list elements
list.forEach(System.out::println);

// A
// B
// C

✌️ Like this article? Follow me on Twitter and LinkedIn. You can also subscribe to RSS Feed.