An array of strings can be joined using the static method String.join()
:
String[] elements = { "foo", "bar", "foobar" };
String singleString = String.join(" + ", elements);
System.out.println(singleString); // Prints "foo + bar + foobar"
Similarly, there's an overloaded String.join()
method for Iterable
s.
To have a fine-grained control over joining, you may use StringJoiner class:
StringJoiner sj = new StringJoiner(", ", "[", "]");
// The last two arguments are optional,
// they define prefix and suffix for the result string
sj.add("foo");
sj.add("bar");
sj.add("foobar");
System.out.println(sj); // Prints "[foo, bar, foobar]"
To join a stream of strings, you may use the joining collector:
Stream<String> stringStream = Stream.of("foo", "bar", "foobar");
String joined = stringStream.collect(Collectors.joining(", "));
System.out.println(joined); // Prints "foo, bar, foobar"
There's an option to define prefix and suffix here as well:
Stream<String> stringStream = Stream.of("foo", "bar", "foobar");
String joined = stringStream.collect(Collectors.joining(", ", "{", "}"));
System.out.println(joined); // Prints "{foo, bar, foobar}"