I am very new to coding and I am struggling with one of my intro to Java Projects. This project involves creating a GUI that has a list of trees and their possible heights, giving each tree a range for their possible minimum and maximum heights.
I am having trouble creating this method for the TreeDatabase (TreeDB class):
public String queryByPossibleHeight(int key) Instructions for this method are as follows: this method creates and returns a single string that contains the trees that can be found such that the value key is in the range for possible height. Traverse the entire ArrayList of Trees and for each one of the trees contained in the ArrayList invoke the method inRange() from the class Tree. Pass to the method inRange() the parameter key. If inRange() returns true, invoke the method toString() from the class Tree. Append the value returned by invoking the method toString() to the String result, adding a “” at the end. Once the entire ArrayList has been traversed, return the String result.
My 3 classes so far (I haven't gotten to the actual GUI yet):
public class Range {
private int low;
private int high;
private int value;
public Range(int plow,int phigh){
low = plow;
high = phigh;
[Code]...
As you can see in the last TreeDB class, in the public String queryByPossibleHeight(int key) method I have something wrote in, but I was just testing random things.
I have to make a method called search that goes through the linked list and checks to see if whatever String the user entered matches a String in the linked list. With this code, every time I enter an existing String it outputs "There is no element that contains that information". How come?
public class LinkedListExample { List InfoList = new LinkedList(); public void doLinkedListExample() { // add original data to linked list InfoList.add("Computer"); // string (original 3 elements) InfoList.add("Programs"); InfoList.add("in Java");
// 1 ***** student writes this method /** Searches for key in integer array named arr // arr is an instance variable of the class and has been instantiated and filled with random values. // @param key value to search for // @return if key is found, the index of the first element // in array whose value is key; if key is not found, // the method returns -1 */
public int sequentialSearch( int key ) { // Note: To animate the algorithm, put this method call as the first statement in your for loop // animate( i, 0 ); // where i is the index of the current array element return 0; // replace this statement with your return statement } // end of sequentialSearch
I am having some trouble with linear search of a customers last name. I can't seem to get it to work. I have looked up examples but cant find many with Array Lists. Here is my code.
import java.util.ArrayList; import java.util.Scanner; public class AccountDriver { public static void main(String[] args) { ArrayList<Account> al = new ArrayList<Account>(); ArrayList<Customer> cust = new ArrayList<Customer>(); Scanner scan = new Scanner(System.in);
I try to create a jsf project within ejb which is add new car with entering attributes listing attributes and search by make.
Add and list methods working well , but have problem of list method. I tryed many combinations (using enhanced loop, iterative loop) but i cant provide working well. Always outputText returns nothing ,when i enter attributes.
Here is ejb code for adding ,getting and listing car items :
@Stateful public class CarsBusiness implements CarsBusinessLocal { List<Car> cars; public CarsBusiness() { cars = new ArrayList<Car>();
I have done this before in C++ but now I want to do it in Java. I am not sure how to iterate through a ArrayList, I have look several places because lets be honest the first stop is normally google. I tried the examples but with no luck.
package org.search.BFS; import java.util.Queue; public class BFS extends Graph { private Queue<Integer> q; BFS(int s) { //mark all the vertices as not visited.
Also the below is giving me a Type safety: The expression of type ArrayList[] needs unchecked conversation to conform to ArrayList<Integer>[]
This is the code fragment I have for searching my ArrayList. Now, each contact is stored in the ArrayList with five elements (first name, last name, etc.) and they're Strings. The error I get when I try to compile my program lies within this code fragment. It says it cannot find the symbol for the search method. I'm not quite sure what to do with this error.
int foundIndex = SAAddressBook.search(aBook); System.out.println(); if (foundIndex > -1) aBook.get(foundIndex).displayContact(); else { System.out.println("No Entry Found"); }
I'm having an issues with adding integer values to a string list. The question is asking me "the method should iterate over runners, and for each runner generate a random number between 90 and 180 (inclusive) which should be used to set the time (in minutes) for that runner."
I have been able to get the random number and iterating over the runner arraylist but I haven't been able to figure out how to add the values generated into the runners list. I am also using BlueJ.
Here's the whole code I have at the moment:
import java.util.*; import java.io.*; import ou.*; import java.util.Random; /** * Write a description of class MarathonAdmin here. */ public class MarathonAdmin { // instance variables - replace the example below with your own
i am interested to add integer objects and String objects into any collection object ..... while iterating the collection object i am not interested to do any type cast in java
I'm doubted regarding the implementation of Collections.binarySearch() method on an ArrayList of objects of a custom class Movie.
Here is the movie class :
public class Movie implements Comparable<Movie> { String movieName; String rating; String director; String theme;
[Code] .....
The sort/binarySearch in searchByMovieName function is done with natural sorting (and Comparable Interface in Movie class). I mean no comparators involved here. And the comparator that I used for sorting/binarySearching on Movies Director attribute in searchByMovieDirector function is :
public class MovieDirectorComparator implements Comparator<Movie> { public int compare(Movie movie1, Movie movie2) { return movie1.getDirector().compareToIgnoreCase(movie2.getDirector()); } }
But I was not able to implement binarySearch ?? How to implement the binarySearch here. I have google to see only binarySearch working on Arrays or probably ArrayList of String only, but not on ArrayList of custom objects.
How do I code this without having the need to use iterator? Code a Java method that accepts an ArrayList of integers and an integer. The method should delete all elements in the array list exactly divisible by the integer and return the number of remaining elements.
I have a my result set object which has data as shown by the attached image.What i am trying to do is traverse these results and do certain operations. I want my program to do this, if I
I have to make a program that allows the user to make a linked list of Strings (names) and then choose who to eliminate.
For example: Five people in a linked list of Strings: I would like the program to ask the user to choose a number between 1 and 5. If the user chooses number 2, Mary is the second person in the linked list so she gets eliminated.
The problem is that I'm not sure how to traverse through the linked list because they are of type String value, and I am looking for the name using the corresponding integer I mentioned above. I think I have to use Nodes? Not very sure where to start right now.Here is my code:
AddItemToFront(Item p) : This method will create a new Node with the Item object as its data value and then add the newly created node to the front of the linked list.
DisplayItems(): This method will traverse the linked list from first node to last node and print data value ( i.e., id, name, type and price of the Item object) of each node.
RemoveItemAtPosition(int n): This method will remove the node at position n in the linked list. Assume that the first node of the linked list has a position number of 1 and the second node has a position number of 2 and so on.
This is my Code
AddItemToFront public void AddItemtoFront(Item p) { Node newNode = new Node(p); newNode.setLink(head); head = newNode;
[Code] ....
I don't know what am I suppose to do inside the remove method
This is my first time using linked lists and for homework I have to make a program that allows the user to make a linked list of Strings (names) and then choose who to eliminate. For example,
Five people in a linked list of Strings: Joe, Mary, Sue, Tom, Hannah.
I would like the program to ask the user to choose a number between 1 and 5. If the user chooses number 2, Mary is the second person in the linked list so she gets eliminated.
The problem is that I'm not sure how to traverse through the linked list because they are of type String value, and I am looking for the name using the corresponding integer I mentioned above.
Here is my code:
package llchallenge; import java.util.LinkedList; import java.util.List; import java.util.ListIterator; import java.util.Scanner; public class LLChallenge { List JosephusList = new LinkedList(); // order of names
I'm trying to build a method that can search a binary search tree for a specific target and then return the number of probes it took to get there. It seems to me that the best way to do this would be a recursive search method and a counter that tracks the number of calls. But I'm struggling with how to implement this. Here's the code I have so far. what works/doesn't work with the method.
// Method to search the tree for a specific name and // return the number of probes public T search(BTNode<T> btNode) {
Object in my main class, it doesn't work as its supposed to. I might be implementing it wrong.
Java Code:
public PostOrderIterator<E> implements Iterator<E>{ Deque<BNode<E>> somestack = new LinkedList<BNode<E>>(); BNode<E> position; public POIterator(BNode<E>root){ somestack = new LinkedList<BNode<E>>(); somestack.push(root);}
public class MyInteger { private int value; public MyInteger(int number){ value = number; System.out.println("Constructor created with value of " + value);
[code]....
I can't seem to get the value for integer1 and integer2 to pass with the setValue method. I get a runtime error stating the I need to have an int value for these two integers.
I have stumbled onto a problem with ArrayLists (not sure if nested ArrayList objects would be a more accurate description) ....
As simply put as I can describe it, I have an Inventory class which creates an ArrayList of a Product superclass, which has two subclasses, PerishableProduct and ItemisedProduct.
By default, the program is meant to have a starting inventory, which is why I have added them in the constructor
public class Inventory { private List<Product> products; public Inventory() { addProduct(new Product("Frying pan", 15, 20)); addProduct(new PerishableProduct("Apple", 5.8, 30, 7)); addProduct(new ItemisedProduct("Cereal", 5.8, 0)); // this is where I am having problems. Wanting to add // objects to the ItemisedProduct's ArrayList for cereal. }
Within the ItemisedProduct subclass is yet another ArrayList which is meant to hold serial numbers.
public class ItemisedProduct extends Product { private ArrayList<String> serialNumbers = new ArrayList(); public ItemisedProduct(String name, double price, int qty) { super(name, price, qty)
[Code] .....
My problem is that I do not know how to populate the serialNumbers ArrayList from the Inventory class' constructor. Because technically, quantity is defined by how many serial numbers are created.
I'm trying to create a booklist in java using swings but I'm facing a problem. I don't know how to add a search function to my list. I need a search box with the book names.
