![How do you update an address according to this code?
Currently, I figured out up to (the bolded line) How do I update address, display all entries and
quit.
Add a name (n)
Look up a name (l)
Update address (u)
Delete an entry (d)
Display all entries (a)
Quit (q)
-> n
import java.util.Scanner;
public class AddressBook {
public static void main(String[] args) {
Tablea addressBook = new Tablea();
Scanner scanner = new Scanner(System. in );
String key, value;
// Insert a new entry into the address book
System. out .print("Enter a name: ");
key = scanner.nextLine();
System. out .print("Enter a address: ");
value = scanner.nextLine();
addressBook.insert(key, value);
// Lookup an entry in the address book
System. out .print("Enter a name to look up: ");
key = scanner.nextLine();](https://image.slidesharecdn.com/howdoyouupdateanaddressaccordingtothiscode-currently-ifig-230310011528-12c07a5c/85/How-do-you-update-an-address-according-to-this-code-Currently-I-fig-pdf-1-320.jpg)
How do you update an address according to this code- Currently- I fig.pdf
- 1. How do you update an address according to this code? Currently, I figured out up to (the bolded line) How do I update address, display all entries and quit. Add a name (n) Look up a name (l) Update address (u) Delete an entry (d) Display all entries (a) Quit (q) -> n import java.util.Scanner; public class AddressBook { public static void main(String[] args) { Tablea addressBook = new Tablea(); Scanner scanner = new Scanner(System. in ); String key, value; // Insert a new entry into the address book System. out .print("Enter a name: "); key = scanner.nextLine(); System. out .print("Enter a address: "); value = scanner.nextLine(); addressBook.insert(key, value); // Lookup an entry in the address book System. out .print("Enter a name to look up: "); key = scanner.nextLine();
- 2. String result = addressBook.lookUp(key); if (result != null) { System. out .println("address: " + result); } else { System. out .println("name not found"); } // Delete an entry from the address book System. out .print("Enter a name to delete: "); key = scanner.nextLine(); boolean deleted = addressBook.delete(key); if (deleted) { System. out .println("address deleted"); } else { System. out .println("name not found"); } } } public class Node { private String key; private String value; private Node next; Node() { // add here ..
- 3. } Node(String key, String value) { // add here .. this.key = key; this.value = value; this.next = null; } public String getKey() { // add here .. return this.key; } public void setKey(String key) { // add here .. this.key = key; } public String getValue() { // add here .. return this.value; } public void setValue(String value) { // add here .. this.value = value; }
- 4. public Node getNext() { // add here .. return this.next; } public void setNext(Node next) { // add here .. this.next = next; } } import java.util.Scanner; public class Tablea { private Node mark; public Node getMark() { return this.mark; } public void setMark(Node mark) { this.mark = mark; } public boolean insert(String key, String value) { Node newNode= new Node(key,value); if (this.mark== null) { this.mark = newNode; }else {
- 5. newNode.setNext(this.mark.getNext()); this.mark.setNext(newNode); } return true; } public String lookUp(String key) { Node current = this.mark; while(current!=null) { if (current.getKey().equals(key)) { return current.getValue(); } current = current.getNext(); } return null; } public boolean delete(String key) { Node current = this.mark; Node prev = null; while (current!= null) { if (current.getKey().equals(key)) { if (prev == null) { this.mark = current.getNext(); }else {
- 6. prev.setNext(current.getNext()); } return true; } prev = current; current = current.getNext(); } return false; } public boolean update(String key, String newValue) { Node current = this.mark; while (current != null) { if (current.getKey().equals(key)) { current.setValue(newValue); return true; } current = current.getNext(); } return false; } public boolean markToStart() { if (this.mark== null) { return false;
- 7. } this.mark = null; return true; } public boolean advanceMark() { if (this.mark== null) { return false; } this.mark = this.mark.getNext(); return true; } public String keyAtMark() { if (this.mark== null) { return null; } return this.mark.getKey(); } public String valueAtMark() { if (this.mark== null) { return null; } return this.mark.getValue(); }
- 8. public int displayAll() { Node current = this.mark; int count = 0; while (current != null) { System. out .println(current.getKey()+":"+ current); } return count; } }