List-specific iterator-Special Functions of ListIterator, list iterator

List-specific iterator-Special Functions of ListIterator, list iterator

/**
*List iterator:
* ListIterator listIterator (): List set unique iterator
* This Iterator inherits the Iterator, so you can directly use the hasNext () and next () methods.
*Special features:
* Object previous (): gets the previous element.
* Boolean hasPrevious (): determines whether the previous element exists.
*
*Note:ListIterator can traverse the list in reverse order, but the premise is that the list can be traversed first and then reversely. Generally, it is not used.
*
*

Import java. util. arrayList; import java. util. list; import java. util. listIterator;/*** List Iterator: * ListIterator listIterator (): List Set-specific Iterator * This Iterator inherits the Iterator. Therefore, you can directly use the hasNext () and next () methods. * Special function: * Object previous (): gets the previous element * boolean hasPrevious (): determines whether the previous element exists. ** Note: ListIterator can traverse the list in reverse order, however, the premise is that a forward traversal can be performed before reverse traversal. Generally, it is not used. **/Public class ListIteratorDemo {public static void main (String [] args) {List list = new ArrayList (); list. add ("hello"); list. add ("world"); list. add ("java"); // actively traverses ListIterator liter = list. listIterator (); while (liter. hasNext () {String s = (String) liter. next (); System. out. println (s);} System. out. println ("---------------------"); // reverse traversal while (liter. hasPrevious () {String s = (String) liter. previous (); System. out. println (s );}}}