I am trying to display the contents of my Object but when I compile it I get this:proj4.TellerQueue@1db9742
I am pretty sure it's because I havent created my own toString method but I could be wrong. If this is the case, what do I need to do to properly display the variables of my object? Right now my class, BankQueue, contains another object called Person, which contains a String and int variables. I want to do something like this:
class BankQueue{
Queue<Person> q = new LinkedList<Person>();
public String toString(){
return q.;//display contents of the q
[code]...
but Im not sure how to convert these into Strings.
I am converting String to date object while converting this i am getting Run time Exception. Here in this code i am using String tokennizer reading a data from a text file. Here is my code
public static void main(String[] args)throws Exception { FileReader fr = new FileReader("g:abc.txt"); BufferedReader br = new BufferedReader(fr); String line = br.readLine();
So I'm working on a project and noticed that my toString() method won't work. This is just an example of the type of code that I have in my real project. THIS IS MY MAIN CLASS
XML Code:
package trialanderror; import java.util.Scanner; public class TrialAndError { public static void main(String[] args) { Scanner keys = new Scanner(System.in); String name; String phonenumber;
>>> Student s = new Student("Roll No", "Name"); >>> System.out.println(s);
Then it gives output according to the way that toString() of Student is implemented,right ? What if I wanna do the same for arrays?? I mean to ask, let us say I have array int[] arr = { 1, 2, 3, 4, 5}. When I say System.out.println(arr), it should give the output as it gives for collections [1,2,3,4,5].
I know that Arrays.toString(int[]) can work for us in this regard. But my question is that can we write our own toString() method so that when I print the "arr" (an Object itself) it should call the toString() that we implemented like a callback function.
I've been trying to make a class that has a toString method that displays the board at the same time displays the value of each index of a 2d character array inside of the code. My professor has made the client print the method. I assumed since he was printing it on the client we had to return a string that gives us this.The number 2 is part of the 2d character array while the rest of the index values are just space characters.
I had trouble figuring out how to return this so I started testing it out in another file.
public static void main(String[] args) { // TODO Auto-generated method stub char[][] myHidingPlaces; myHidingPlaces = new char[5][3]; myHidingPlaces[0][0] = 'p'; char play = '1'; for (int i = myHidingPlaces.length-1; i >= 0 ; i--) {
My current assignment involves me outputting these 2 classes. Yet I'm not really sure in what manner I should go about doing this. I have tried creating a separate class and outputting my toString methods there but for some reason I am getting an error. .
The error message is thus;
Exception in thread "main" java.lang.NullPointerException at Vehicle.toString(Vehicle.java:91) at Run.main(Run.java:17) Process completed.
Write TestCabAppointment,java class where you will instantiate new CabAppointment objects and read data from RandomAccessFile and create CabAppointment objects and save them in RandomAccessFile You may use FixedLengthStringIO,java class, ICabAppointmentRecord.java interface. Complete the ReadWriteRandomAccessFile.java
what im trying to do is modify the Coin class to override the toString() method so that it indicates whether the coin is face up or face down. For example, "The coin is face up." This is what i have so far:
public class Coin { public static void main(String[] args) { Coin coin = new Coin(); for (int i = 0; i < 1; i++) { coin.flip(); System.out.println(coin);
How do i print override the toString for WebBrowser as i would like to print out the object bc. Tested the program and it is fine if i put it in the main method rather than the WebBrowser constructor.
import java.util.*; class ListNode <E> { /* data attributes */ private E element; private ListNode <E> next; /* constructors */ public ListNode(E item) { this(item, null);
So I have to write all the methods for a LinkedListQueue. I've got isEmpty, enqueue and dequeue working correctly (I think) but I'm having trouble with the toString method. I tried to do it recursively and it works if there is only one element in the list, but with multiple elements it throws a StackOverflowerror exception. I've tried it multiple different ways, but I can't seem to figure out how to print it out with out clearing everything. We haven't been taught StringBuilder or .append yet, which I saw a lot of as I was looking for solutions, so I can't use those.
public class LinkedQueue<T> { protected LLNode<T> front; // reference to the front of this queue protected LLNode<T> rear; // reference to the rear of this queue private T info; public LinkedQueue() { front = null; rear = null;
[Code] ....
and this is the ITD used with it, for some reason it has the "empty the queue" function as a choice but we weren't assigned that function, so just ignore it.
import java.util.Scanner; public class ITDLinkedQueue { public static void displayMenu() { System.out.println("(1) display menu"); System.out.println("(2) check isEmpty"); System.out.println("(3) enqueue"); System.out.println("(4) dequeue");
Our goal is to write a pretty simple program, one that takes the 12 digit UPC code entered by a user and to not only spit it back out in a format with dashes using toString, and also returns the first digit, a 2 more groups of digits numbering 2-6 and 7-11, and finally display the 12th digit. It then performs an equation to check the last digit and make sure the UPC code is correct.
However, being so new to java (I only learned visual basic before), with this I was introduced to two new concepts that for some reason I simply cannot grasp for the life of me: Using and calling the toString method, and calling on methods that are created in a completely different class file.
The first section of code is my UPC class, which is meant to contain all my methods as well as the toString to be called on:
public class UPC { // Instance variables private int itemType; // digit 1 private int manufacturer; // digits 2,3,4,5,6 private int product; // digits 7,8,9,10,11 private int checkDigit; // digit 12
Write a class encapsulating the concept of a course grade, assuming a course grade has the following attributes: a course name and a letter grade. Include a constructor, the accessor and mutator, and methods toString and equals.Write a client class to test all the methods in your class.
how to test and finish the toString and equals method in this code ?
package labmodule7num57; import java.util.*; public class LabModule7Num57 { // Constructors// private String name; private String letterGrade; public LabModule7Num57 (String name,String letterGrade) {
I need making the toString() method return a String rather than display a message to the screen. Also, I'm not supposed to call the toString method in my demo class to test it, so what should I do instead?
public class cupDispenser { String location; int noOfCups; cupDispenser(String location,int cups) { this.location=location; this.noOfCups=cups; } public String getlocation()
Create an equals method that takes an object reference and returns true if the given object equals this object.
Hint: You'll need 'instanceof' and cast to a (Geocache)
So far I have:
public boolean equals(Object O){ if(O instanceof Geocache){ Geocache j=(Geocache) O; if (this.equals(j)) //I know this is wrong... but I can't figure it out return true; }
else return false; }
I think I have it correct up to the casting but I don't understand what I'm suppose to do with the this.equals(). Also I'm getting an error that I'm not returning a boolean... I get this all the time in other problems. I don't get why since I have to instances of returning booleans in this. "returns true if the given object equals this object" makes no sense to me. I assume the given object, in my case, is 'O'. What is 'this' object referring to?
I am new to Java and have read books, the Java docs, and searched the Internet for my problem to no avail. I have an Array of objects that contains strings. How can I get the object's strings to print in a list so that the user can select that object to manipulate its attributes? For example, the user can select "Guitar 1" from a list and manipulate its attributes like tuning it, playing it, etc. I have a class called Instruments and created 10 guitar objects.Here is the code:
Instrument [] guitar = new Instrument[10]; for (int i = 0; i < 10; i++) { guitar[0] = new Instrument("Guitar 1"); guitar[1] = new Instrument("Guitar 2"); guitar[2] = new Instrument("Guitar 3"); guitar[3] = new Instrument("Guitar 4"); guitar[4] = new Instrument("Guitar 5"); guitar[5] = new Instrument("Guitar 6");
Now lets say that I want to access a method 'addInterest()' that is in the 'SavingsAccount' class I would have to do: '((SavingsAccount)s).addInterest();'
The question I have is why do I have to cast 'b' to SavingsAccount? Isn't the actual object reference of 'b' already an instance of 'SavingsAccount' class? How does the 'BankAccount' affect the object itself? I'm really confused as to what class is truly getting instantiated and how BankAccount and SavingsAccount are both functioning to make the object 'b'.
I don't understand why the object reference variable 'a' cannot be recast from a thisA object reference to a thisB object reference.Is it the case that once a reference variable is linked to a particular object type then it cannot switch object types later on.I am facing the Java Associate Developer exam soon and I am just clearing up some issues in my head around object reference variable assignment,
class thisA {} class thisB extends thisA { String testString = "test";} public class CastQuestion2 { public static void main(String[] args) { thisA a = new thisA(); thisB b = new thisB();
I am trying to get this to where I can type in a name and it will search through each object and print back the corresponding object info.
Java Code:
import java.util.Scanner; public class MyPeople { public static void main(String[] args) { Person[] p = new Person[] { new Person("Chris", 26, "Male", "NJ", "Single"), new Person("JoAnna", 23, "Female", "NJ", "Single"), new Person("Dana", 24, "Female", "NJ", "Single"), new Person("Dan", 25, "Male", "NJ", "Single"), new Person("Mike", 31, "Male", "NJ", "Married") };
