// 1
String[] s1 = {"hello", "world"};
// 2
String[] s2 = new String[]{"hello", "world"};
// 3
String[] s3 = new String[2];
s3[0] = "hello";
s3[1] = "world";
// 4 java 8
String[] s4 = Stream.of("hello", "world", "ok").toArray(String[]::new);
for (String item: s1) {
System.out.println(item);
}