if I use a for-each loop on a linked list in java, is it guaranteed that I will iterate on the elements in the order in which they appear in the list?
I found 5 main ways to iterate over a Linked List in Java (including the Java 8 way):
For loop
LinkedList<String> linkedList = new LinkedList<>();
System.out.println("==> For Loop Example.");
for (int i = 0; i < linkedList.size(); i++) {
System.out.println(linkedList.get(i));
}
Enhanced for loop
for (String temp : linkedList) {
System.out.println(temp);
}
While loop
int i = 0;
while (i < linkedList.size()) {
System.out.println(linkedList.get(i));
i++;
}
Iterator
Iterator<String> iterator = linkedList.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
collection stream() util (Java 8)
linkedList.forEach((temp) -> {
System.out.println(temp);
});
One thing should be pointed out is that the running time of For Loop or While Loop is O(n square) because get(i)
operation takes O(n) time(see this for details). The other 3 ways take linear time and performs better.