String.join()
Joins strings with a separator.
Available since: Java 8
Syntax
static String join(CharSequence delimiter, CharSequence... elements)Parameters
| Parameter | Type | Description |
|---|---|---|
| delimiter | CharSequence | The string inserted between elements. |
| elements | CharSequence... / Iterable | Strings separated by commas, an array or a collection of strings (for example a list). |
Return value
StringOne string made of all the elements.
Examples
From separate strings and from a list:
void main() {
IO.println(String.join("-", "2025", "03", "14"));
List<String> names = List.of("Anna", "Oleg", "Maria");
IO.println(String.join(", ", names));
}Output:
2025-03-14
Anna, Oleg, MariaNotes
The separator goes only between elements, not at the end. For lists of numbers use a stream: numbers.stream().map(String::valueOf).collect(Collectors.joining(", ")).
See also
- String.split() — Splits a string into an array of parts by a separator.
- StringBuilder — A mutable string: useful when text is built piece by piece, especially in a loop.
- String.repeat() — Repeats a string the given number of times.
- Collectors.joining() — A collector that joins the strings of a stream into one.
Related recipes
In the tutorial
- String methods — The main String methods in Java: searching, substring, changing case, strip, replace, split, join, repeat and string checks.