Fix the following null pointer error.
import java.util.*;
import java.io.*;
public class PhoneBook {
public static void main(String[]args)throws IOException {
PhoneBook obj = new PhoneBook();
PhoneContact[]phBook = new PhoneContact[20];
Scanner in = new Scanner(System.in);
obj.acceptPhoneContact(phBook,in);
PrintWriter pw = new PrintWriter("out.txt");
obj.displayPhoneContacts(phBook,pw);
pw.close();
}
public void acceptPhoneContact(PhoneContact[]phBook, Scanner k) { //void function that takes in the parameters
//phBook array and the scanner so the user can input the information
//declaring these variables
String fname = "";
String lname = "";
String contact = "";
String option = "";
System.out.println("Do you have any new contacts to enter? Enter zzz to exit. ");
option = k.next(); //enter yes or no and the output is stored in the option variable
int count = 0; //initialize count to 0
if(phBook[0] != null) { //this checks if the phBook is empty or not
count = getCurrentContactCount(phBook); //if yes, it will display an integer and value assigned to count
}
else {//if not, the phone book is empty and a message will be displayed saying that its empty
System.out.println("Phone book is empty");
count = 0;
}
while(!(option.contentEquals("zzz")) && count <= 20) { //while loop that will continue to ask
//the user for more contacts if there are not 20 contacts already and if the user does not enter zzz
System.out.println("Enter first name: ");
fname = k.next(); //after entering in the name; it stores it in the fname variable
System.out.println("Enter last name: ");
lname = k.next();
System.out.println("Enter phone number: ");
contact = k.next();
if(option.contentEquals("zzz")) {
break;
}
if(phBook[0] != null) { //if this is not empty it will look for a contact
if(searchContact(phBook, fname, lname, contact) != null) {//if this is not empty, it'll say the contact exists
System.out.println("Contact exists");
System.out.println(searchContact(phBook, fname, lname, contact));
break;
}else {//otherwise it will add the contact to the phone book
phBook[count] = new PhoneContact(fname, lname, contact);
count++;
if(count >= 20) {
System.out.println("You have reached the maximum number of contacts.");
break;
}
}
}
else {//if the phone book array is empty then it will print that the phone book is empty and add the contact
System.out.println("Phone book is empty");
phBook[count] = new PhoneContact(fname, lname, contact);
count++;
}
System.out.println("Do you have any new contacts to enter? ");
option = k.next();
}//ends while loop; if the user wants to exit and no longer enter in contacts they will type zzz
System.out.println("The phone book has " + count + " contacts");
}
public int getCurrentContactCount(PhoneContact[]phBook) {
int numContacts = 0;
for(int a = 0; a < phBook.length; a++) {
if(phBook[a] != null) {
numContacts++;
}
}
return numContacts;
}
public PhoneContact searchContact(PhoneContact[]phBook, String fname, String lname, String phone) {
PhoneContact contact= null;
for(int a= 0 ; a < phBook.length ; a++) {
if(phBook[a] != null && phBook[a].getfirstName().equals(fname)) {//compare lname and phone contact
System.out.println("Phone book conatct exists");
contact = phBook[a];
break;
}
}
return contact;
}
public void displayPhoneContacts(PhoneContact[]phBook, PrintWriter pw)
throws IOException{
pw.println("Phone Book");
pw.println("**************************");
pw.print("First Name\tLast Name\t Contact number");
for(int a= 0 ; a < phBook.length ; a++) {
pw.println(phBook[a].getfirstName() +"\t" + phBook[a].getlastName()+"\t" + phBook[a].getphoneNumber());
}
}
}
import java.util.*;
import java.io.*;
class PhoneContact{
String fname,lname,phoneNum;
PhoneContact(String f,String l,String c){
this.fname=f;
this.lname=l;
this.phoneNum=c;
}
public String getFname() {
return fname;
}
public void setFname(String fname) {
this.fname = fname;
}
public String getLname() {
return lname;
}
public void setLname(String lname) {
this.lname = lname;
}
public String getPhoneNum() {
return phoneNum;
}
public void setPhoneNum(String phoneNum) {
this.phoneNum = phoneNum;
}
public String getfirstName() {
return this.fname;
}
public String getlastName() {
return this.lname;
}
public String getphoneNumber() {
return this.phoneNum;
}
}
public class PhoneBook {
public static void main(String[]args)throws IOException {
PhoneBook obj = new PhoneBook();
PhoneContact[]phBook = new PhoneContact[20];
Scanner in = new
Scanner(System.in);
obj.acceptPhoneContact(phBook,in);
PrintWriter pw = new
PrintWriter("out.txt");
obj.displayPhoneContacts(phBook,pw);
pw.close();
}
public void acceptPhoneContact(PhoneContact[]phBook,
Scanner k) { //void function that takes in the parameters
//phBook
array and the scanner so the user can input the information
//declaring
these variables
String fname
= "";
String lname =
"";
String contact =
"";
String option =
"";
int count =
0;
System.out.print("Do you have any new contacts to enter(yes)? Enter
zzz to exit: ");
option =
k.nextLine();
while(!(option.contentEquals("zzz")) && count < 20) {
//while loop that will continue to ask
//the user for more contacts if there are not 20
contacts already and if the user does not enter zzz
System.out.print("Enter first name: ");
fname = k.nextLine(); //after entering in the
name; it stores it in the fname variable
System.out.print("Enter last name: ");
lname = k.nextLine();
System.out.print("Enter phone number: ");
contact = k.nextLine();
if(phBook[0] != null) { //if this is not empty
it will look for a contact
if(searchContact(phBook,
fname, lname, contact) != null) {//if this is not empty, it'll say
the contact exists
System.out.println("Contact exists");
}else {//otherwise it will
add the contact to the phone book
phBook[count] = new PhoneContact(fname, lname, contact);
count++;
if(count
>= 20) {
System.out.println("You have reached the maximum
number of contacts.");
break;
}
}
}else {//if the phone book array is empty then
it will print that the phone book is empty and add the
contact
if(count==0)
System.out.println("Phone book is empty");
phBook[count] = new
PhoneContact(fname, lname, contact);
count++;
}
System.out.print("\nDo you have any new contacts
to enter(yes)?Enter zzz to exit: ");
option = k.nextLine();
}//ends while
loop; if the user wants to exit and no longer enter in contacts
they will type zzz
System.out.println("The phone book has " + count + "
contacts");
}
public int
getCurrentContactCount(PhoneContact[]phBook) {
int numContacts = 0;
for(int a = 0; a <
phBook.length; a++) {
if(phBook[a] !=
null) {
numContacts++;
}
}
return numContacts;
}
public PhoneContact
searchContact(PhoneContact[]phBook, String fname, String lname,
String phone) {
PhoneContact contact= null;
int
n=getCurrentContactCount(phBook);
for(int a= 0 ; a < n ; a++)
{
if(
phBook[a].getfirstName().equalsIgnoreCase(fname) &&
phBook[a].getlastName().equalsIgnoreCase(lname) &&
phBook[a].getPhoneNum().equalsIgnoreCase(phone)) {//compare lname
and phone contact
System.out.println("Phone book conatct
exists");
contact = phBook[a];
break;
}
}
return contact;
}
public void displayPhoneContacts(PhoneContact[]phBook,
PrintWriter pw)
throws
IOException{
int n=getCurrentContactCount(phBook);
pw.println("Phone Book");
pw.println("**************************");
pw.print("First Name\tLast Name\t Contact
number");
for(int a= 0 ; a < n ; a++) {
pw.println(phBook[a].getfirstName() +"\t" +
phBook[a].getlastName()+"\t" + phBook[a].getphoneNumber());
}
}
}
//###########################################################################
OUTPUT
###########
Fix the following null pointer error. import java.util.*; import java.io.*; public class PhoneBook { public static...
I need help running this code. import java.util.*; import java.io.*; public class wordcount2 { public static void main(String[] args) { if (args.length !=1) { System.out.println( "Usage: java wordcount2 fullfilename"); System.exit(1); } String filename = args[0]; // Create a tree map to hold words as key and count as value Map<String, Integer> treeMap = new TreeMap<String, Integer>(); try { @SuppressWarnings("resource") Scanner input = new Scanner(new File(filename));...
Why does my program generate [] when viewing all guests names? ----------------------------------------------- import java.util.*; public class Delete extends Info { String name; int Id; int del; public Delete() { } public void display() { Scanner key = new Scanner(System.in); System.out.println("Input Customer Name: "); name = key.nextLine(); System.out.println("Enter ID Number: "); Id = key.nextInt(); System.out.println("Would you like to Delete? Enter 1 for yes or 2 for no. "); del = key.nextInt(); if (del == 1) { int flag = 0; //learned...
P1 is below package p6_linkedList; import java.util.*; public class LinkedList { public Node header; public LinkedList() { header = null; } public final Node Search(int key) { Node current = header; while (current != null && current.item != key) { current = current.link; } return current; } public final void Append(int newItem) { Node newNode = new Node(newItem); newNode.link = header; header = newNode; } public final Node Remove() { Node x = header; if (header != null) { header...
Cant figure out how to fix error Code- import java.io.File; import java.io.IOException; import java.util.*; public class Program8 { public static void main(String[] args)throws IOException{ File prg8 = new File("program8.txt"); Scanner reader = new Scanner(prg8); String cName = ""; int cID = 0; double bill = 0.0; String email = ""; double nExempt = 0.0; String tExempt = ""; int x = 0; int j = 1; while(reader.hasNextInt()) { x = reader.nextInt();} Customers c1 [] = new Customers [x]; for (int...
Identify a logical error in the following code and fix it. public class test1 { public static void main(String[] args){ int total; float avg; int a, b, c; a=10; b=5; c=2; total=a+b+c; avg=total/3; System.out.println("Average: "+avg); } } Answer: Write the output of the program below. import java.util.Scanner; public class test2 { public static void main(String[] arg){ int psid; String name; Scanner input=new Scanner(System.in); System.out.println("Enter your PSID"); psid=input.nextInt(); System.out.println("Enter your...
JAVA help Create a class Individual, which has: Instance variables for name and phone number of individual. Add required constructors, accessor, mutator, toString() , and equals method. Use array to implement a simple phone book , by making an array of objects that stores the name and corresponding phone number. The program should allow searching in phone book for a record based on name, and displaying the record if the record is found. An appropriate message should be displayed if...
(How do I remove the STATIC ArrayList from the public class Accounts, and move it to the MAIN?) import java.util.ArrayList; import java.util.Scanner; public class Accounts { static ArrayList<String> accounts = new ArrayList<>(); static Scanner scanner = new Scanner(System.in); public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int option = 0; do { System.out.println("0->quit\n1->add\n2->overwirte\n3->remove\n4->display"); System.out.println("Enter your option"); option = scanner.nextInt(); if (option == 0) { break; } else if (option == 1) { add(); } else...
import java.io.*; import java.util.Scanner; public class CrimeStats { private static final String INPUT_FILE = "seattle-crime-stats-by-1990-census-tract-1996-2007.csv"; private static final String OUTPUT_FILE = "crimes.txt"; public static void main(String[] args) { int totalCrimes = 0; // read all the rows from the csv file and add the total count in the totalCrimes variable try { Scanner fileScanner = new Scanner(new File(INPUT_FILE)); String line = fileScanner.nextLine(); // skip first line while (fileScanner.hasNext()) { String[] tokens = fileScanner.nextLine().split(","); if (tokens.length == 4) { totalCrimes +=...
import java.util.Scanner; public class TriangleMaker { public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("Welcome to the Triangle Maker! Enter the size of the triangle."); Scanner keyboard = new Scanner(System.in); int size = keyboard.nextInt(); for (int i = 1; i <= size; i++) { for (int j = 0; j < i; j++) { System.out.print("*"); } System.out.println(); } for (int...
make this program run import java.util.Scanner; public class PetDemo { public static void main (String [] args) { Pet yourPet = new Pet ("Jane Doe"); System.out.println ("My records on your pet are inaccurate."); System.out.println ("Here is what they currently say:"); yourPet.writeOutput (); Scanner keyboard = new Scanner (System.in); System.out.println ("Please enter the correct pet name:"); String correctName = keyboard.nextLine (); yourPet.setName (correctName); System.out.println ("Please enter the correct pet age:"); int correctAge = keyboard.nextInt (); yourPet.setAge (correctAge); System.out.println ("Please enter the...