Java by API/java.util/ListIterator — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Версия 20:43, 31 мая 2010
Содержание
ListIterator: add(T e)
<source lang="java">
import java.util.LinkedList; import java.util.List; import java.util.ListIterator; public class Main{
public static void main(String[] a) { List<String> list = new LinkedList<String>(); list.add("A"); list.add("B"); list.add("C"); list.add("D"); ListIterator<String> iter = list.listIterator(list.size()); while (iter.hasPrevious()) { System.out.println(iter.previous()); iter.add("a"); break; } System.out.println(list); }
}
</source>
ListIterator: hasNext()
<source lang="java">
/**
*Output:
Original contents of al: C A E B D F Modified list backwards: F+ D+ B+ E+ A+ C+
*/
import java.util.ArrayList; import java.util.Iterator; import java.util.ListIterator; public class MainClass {
public static void main(String args[]) { ArrayList<String> al = new ArrayList<String>(); al.add("C"); al.add("A"); al.add("E"); al.add("B"); al.add("D"); al.add("F"); System.out.print("Original contents of al: "); Iterator<String> itr = al.iterator(); while (itr.hasNext()) { String element = itr.next(); System.out.print(element + " "); } System.out.println(); ListIterator<String> litr = al.listIterator(); while (litr.hasNext()) { String element = litr.next(); litr.set(element + "+"); } // Now, display the list backwards. System.out.print("Modified list backwards: "); while (litr.hasPrevious()) { String element = litr.previous(); System.out.print(element + " "); } }
}
</source>
ListIterator: hasPrevious()
<source lang="java">
/**
*Output:
Original contents of al: C A E B D F Modified list backwards: F+ D+ B+ E+ A+ C+
*/
import java.util.ArrayList; import java.util.Iterator; import java.util.ListIterator; public class MainClass {
public static void main(String args[]) { ArrayList<String> al = new ArrayList<String>(); al.add("C"); al.add("A"); al.add("E"); al.add("B"); al.add("D"); al.add("F"); System.out.print("Original contents of al: "); Iterator<String> itr = al.iterator(); while (itr.hasNext()) { String element = itr.next(); System.out.print(element + " "); } System.out.println(); ListIterator<String> litr = al.listIterator(); while (litr.hasNext()) { String element = litr.next(); litr.set(element + "+"); } // Now, display the list backwards. System.out.print("Modified list backwards: "); while (litr.hasPrevious()) { String element = litr.previous(); System.out.print(element + " "); } }
}
</source>
ListIterator: next()
<source lang="java">
/**
*Output:
Original contents of al: C A E B D F Modified list backwards: F+ D+ B+ E+ A+ C+
*/
import java.util.ArrayList; import java.util.Iterator; import java.util.ListIterator; public class MainClass {
public static void main(String args[]) { ArrayList<String> al = new ArrayList<String>(); al.add("C"); al.add("A"); al.add("E"); al.add("B"); al.add("D"); al.add("F"); System.out.print("Original contents of al: "); Iterator<String> itr = al.iterator(); while (itr.hasNext()) { String element = itr.next(); System.out.print(element + " "); } System.out.println(); ListIterator<String> litr = al.listIterator(); while (litr.hasNext()) { String element = litr.next(); litr.set(element + "+"); } // Now, display the list backwards. System.out.print("Modified list backwards: "); while (litr.hasPrevious()) { String element = litr.previous(); System.out.print(element + " "); } }
}
</source>
ListIterator: nextIndex()
<source lang="java">
import java.util.ArrayList; import java.util.ListIterator; public class Main {
public static void main(String[] args) { ArrayList<String> aList = new ArrayList<String>(); aList.add("1"); aList.add("2"); aList.add("3"); aList.add("4"); aList.add("5"); ListIterator<String> listIterator = aList.listIterator(); System.out.println("Previous: " + listIterator.previousIndex()); System.out.println("Next: " + listIterator.nextIndex()); // advance current position by one using next method listIterator.next(); System.out.println("Previous: " + listIterator.previousIndex()); System.out.println("Next: " + listIterator.nextIndex()); }
}
</source>
ListIterator: previous()
<source lang="java">
import java.util.LinkedList; import java.util.List; import java.util.ListIterator; public class Main{
public static void main(String[] a) { List<String> list = new LinkedList<String>(); list.add("A"); list.add("B"); list.add("C"); list.add("D"); ListIterator<String> iter = list.listIterator(list.size()); while (iter.hasPrevious()) { System.out.println(iter.previous()); iter.add("a"); break; } System.out.println(list); }
}
</source>
ListIterator: previousIndex()
<source lang="java">
import java.util.ArrayList; import java.util.ListIterator; public class Main {
public static void main(String[] args) { ArrayList<String> aList = new ArrayList<String>(); aList.add("1"); aList.add("2"); aList.add("3"); aList.add("4"); aList.add("5"); ListIterator<String> listIterator = aList.listIterator(); System.out.println("Previous: " + listIterator.previousIndex()); System.out.println("Next: " + listIterator.nextIndex()); // advance current position by one using next method listIterator.next(); System.out.println("Previous: " + listIterator.previousIndex()); System.out.println("Next: " + listIterator.nextIndex()); }
}
</source>
ListIterator: remove()
<source lang="java">
import java.util.ArrayList; import java.util.ListIterator; public class Main {
public static void main(String[] args) { ArrayList<String> aList = new ArrayList<String>(); aList.add("1"); aList.add("2"); aList.add("3"); aList.add("4"); aList.add("5"); // Get an object of ListIterator using listIterator() method ListIterator listIterator = aList.listIterator(); listIterator.next(); listIterator.next(); // remove element returned by last next method listIterator.remove(); for (String str: aList){ System.out.println(str); } }
}
</source>
ListIterator: set(T e)
<source lang="java">
import java.util.ArrayList; import java.util.ListIterator; public class Main {
public static void main(String[] args) { ArrayList<String> aList = new ArrayList<String>(); aList.add("1"); aList.add("2"); aList.add("3"); aList.add("4"); aList.add("5"); ListIterator<String> listIterator = aList.listIterator(); listIterator.next(); listIterator.set("100"); for (String str : aList) { System.out.println(str); } }
}
</source>