hi danpost
I have decided to leave it jus like that. that it is the only problem with it. everything else is working just perfectly thanks for all of your help, understanding and patience
divinity wrote ...
2016/11/24
java long nullpointerexception
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hi danpost, super_hippo
can someone tell me what causing this error
how do i fix this error
how does it go from insufficient fund to -5 when the balance supposed to say 35.0
how to fix that from the codes posted above I have since removed these lines
Please select your choice now!! 4 Account@3570b0/nID: 3 Balance: -5.0 2 Enter the amount to deposit 10 Balance is 35.0 Enter the amount to withdraw 40 Insufficient amount Balance is: -5.0
public double deposit(double deposit)
{
balance +=deposit;
return(getbalance()+deposit);
}
public double withdraw(double withdraw)
{
balance -=withdraw;
return (getbalance() - withdraw);
You removed these lines? How did you replace them? I think you have to show the whole code again.
this is the main
import java.text.DecimalFormat;
import java.util.Scanner;
public class ATM {
DecimalFormat df = new DecimalFormat("#.00");
public static void main(String[] args) {
createAccount();
}
public static void createAccount()
{
Scanner input = new Scanner(System.in);
int i=0;
double bal=50.0;
Account[] acc = new Account[10];
Person[] p = new Person[i++];
for(i=0; i<acc.length; i++){
System.out.println("Enter first name");
String fn = input.next();
System.out.println("Enter last name");
String ln = input.next();
System.out.println("Enter address");
String ad = input.next();
System.out.println("Enter contact");
String c = input.next();
Person person= new Person(fn, ln, ad, c);
acc[i]= new Account(i, 50, person);
}
while(true)
{
System.out.println("Enter your id");
int id = input.nextInt();
if(id == -1)
{
break;
}
while(id < 0 || id > 9)
{
System.out.println("id is incorect, try again");
id = input.nextInt();
}
while(true)
{
displayMenu();
if(!useMenu(acc[id],input))
{
System.out.println();
break;
}
System.out.println("\n");
}
}
}
public static boolean useMenu(Account acc, Scanner input)
{
int userchoice = input.nextInt();
double amt=0;
if(userchoice == 5)
{
return false;
}
else if(userchoice == 1)
{
System.out.println("The account balance is: "+ acc.getbalance());
return true;
}
else if(userchoice == 2)
{
System.out.println("Enter the amount to withdraw");
acc.withdraw(input.nextDouble());
if(amt > acc.getbalance())
{
System.out.println("Insufficient amount "+ " Balance is: "+acc.getbalance());
}
else
{
acc.withdraw(amt);
}
}
else if(userchoice == 3)
{
System.out.println("Enter the amount to deposit");
acc.deposit(input.nextDouble());
acc.deposit(amt);
System.out.println("Balance is "+ acc.getbalance());
return true;
}
else if(userchoice == 4)
{
System.out.println(acc.toString());
}
else
{
System.out.println("invalid choice");
}
return true;
}
public static void displayMenu()
{
System.out.println("Welcome to the Automated Teller Machine!\n");
System.out.println("Select from the following menu option below:\n");
System.out.println("===================================");
System.out.println("| Main Menu |");
System.out.println("===================================");
System.out.println("| [1] Check Balance |");
System.out.println("| [2] Withdraw |");
System.out.println("| [3] Deposit |");
System.out.println("| [4] Display User Information |");
System.out.println("| [5] Exist |");
System.out.println("===================================");
System.out.println("Please select your choice now!!");
}
}
this is the account class
public class Account
{
private int ID;// this is the id variable
private double balance;
private Person owner;
public Account()
{
//no arg constructor
}
//constructor method with
public Account(int ID, double balance, Person owner)
{
this.ID = ID;
this.balance = balance;
this.owner = owner;
}
public int getID()
{
return ID;
}
public double getbalance()
{
return balance;
}
public Person getowner()
{
return owner;
}
public void setID(int ID)
{
this.ID = ID;
}
public void setbalance(double balance)
{
this.balance = balance;
}
public void setowner(Person owner)
{
this.owner = owner;
}
public void deposit(double amt)
{
balance = balance + amt;
}
public void withdraw(double amt)
{
balance = balance - amt;
}
@Override
public String toString()
{
String getdetails = super.toString()+
"/nID: "+ID+" "
+ "\nBalance: "+balance;
return getdetails;
}
}
this is the person
public class Person {
private String FirstName;
private String LastName;
private String address;
private String contact;
public Person(String f, String l, String a, String c) {
FirstName = f;
LastName = l;
address = a;
contact = c;
}
//get first name
public String getFirstName() {
return FirstName;
}
//get last name
public String getLastName() {
return LastName;
}
//get address
public String getaddress() {
return address;
}
//get telephone number
public String getcontact() {
return contact;
}
//accessor method with the person name and with parameters
public void setFirstName(String FirstName) {
this.FirstName = FirstName;
}
//accessor method with the person last name with parameters
public void setLastName(String LastName) {
this.LastName = LastName;
}
//accessor method the person address with parameters
public void setaddress(String address) {
this.address = address;
}
//accessor method that take one parameter
public void setcontact(String contact) {
this.contact = contact;
}
@Override
public String toString() {
String getdetails = super.toString()
+ "First Name " + FirstName + " "
+ "Last Name " + LastName + " "
+ "Address " + address + " "
+ " Contact " + contact;
return getdetails;
}
}
Okay. Line 76 is making an unconditional withdrawal of the amount input (no balance check has been performed as yet). Then, the 'amt' variable is never assigned any value (other than the initial zero value assigned to it). This should be done on line 76:
amt = input.nextDouble()
thanks danpost
i got that one fixed and now how do i fixed this one. it was working good all the time and now I dont know what d hell went wrong d
this supposed to show the user information
Account@3570b0/nID: 1 Balance: 35.0
Maybe you meant to use this for line 96 of the ATM class:
Also, I do not think you want to use 'super.toString' in the 'toString' methods.
System.out.println(acc.getowner().toString());
hi danpost
i did exactly wat you suggested and this is the result
Person@21b220F- why am i getting this line
Person@21b220First Name joy Last Name joyeau Address arouca Contact 6223535
divinity wrote...
Person@21b220F- why am i getting this linedanpost wrote...
I do not think you want to use 'super.toString()' in the 'toString' methods.hi
I am still getting this error and what do i do if I cannot use the super.toString, how do i get the user information to print if i cannot used the super.toString method
Person@3570b0
You do not need the 'super.toString'. You are overriding the method with your own 'toString' method in those classes. Calling 'toString' on an Account or Person object would normally display that which you are trying to get rid of. If you did not have a 'toString' method in the class, that is what will be returned. When you add the method into the Account or Person class, it will execute that method instead of the one in the super class. But, if you call 'super.toString', you are allowing it to execute again, returning the class name of the object followed by a pointer to where the object is stored in memory. Just remove 'super.toString()+' from your 'toString' methods in those classes. The user information should still print out.
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