**NO ARRAYLIST IS ALLOWED!** And the textfile is passed into the method. How to get the size for the array non-randomly inside the method from the passed Scanner file?? What if you have lots of numbers of lines, so how could that be done?
I have doubts about this line Exam[] object = new Exam[12];
I am taking the Class Algorithms and Datastructures and got an assignment for Lab that really throws me off. The goal is to create an Array out of a given CSV file, implement several Methods that get the size of array, etc.
I am still stuck in the first part where the CSV has to be imported into the Array. My problem is that I need a mechanism that figures out the needed size for the Array, creates the array, and only then transfers the data from the CSV.
The list consists of the following wifi related values:
MAC-Adress, SSID, Timestamp, Signalstrength.
These are on the list, separated by comma. The Columns are each of these, and the rows are the four types of values making up the information on a certain wifi network.
The catch is, we are not allowed to use any of the following:
java.util.ArrayList java.util.Arrays and any class out of java.util.Collection.
So far I used the BufferedReader to read in the file and tried to implement the array, but I get an arrayindexoutofboundsexception.
Below is my Code (Its still an active construction zone):
public class WhatsThere { public WhatsThere(String wifiscan) throws IOException { } public static void main(String[] args) throws IOException { // WhatsThere Liste = new WhatsThere(String wifiscan); String[][] arrayListe = new String[0][0];
The array size is fixed improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array into it .I am using a course class and here is the code for the class
public class Course { private String courseName; private int numberOfStudents; private String[] students = new String[100]; public Course(String courseName)
[Code] ....
As you can see I have the array set to size 100, how do i make so it increments each time the user adds a student.
I come to the point: I just started to learn java through various manuals and in one of them I came across a declaration of an array that I do not understand:
int[][] multiArr = new int[2][];
the manual says that you can allocate the multidimensional array multiArr by defining size in only the first square bracket but I can't undestand how you can use this array. Seems to be no way to store data with it!
I'm working on an assignment that says the following.
" The array size is fixed in Listing 10.6. Improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array to it.Implement the dropStudent method.Add a new method named clear() that removes all students from the course.
Write a test program that creates a course, adds three students, removes one, and displays the students in the course."
10.6 Listing
public class Course { private String courseName; private String[] students = new String[100]; private int numberOfStudents; } public Course(String courseName) { this.courseName= courseName;
[Code]...
My Test Code based off of book
public static void main(String[] args) { Course course1= new Course("Business"); course1.addStudent("Jay"); course1.addStudent("Silent Bob"); course1.addStudent("Dante"); course1.dropStudent("Jay");
[Code]....
My adjusted 10.6
public class Course { private String courseName; private String[] students = new String[100]; private int numberOfStudents; } public Course(String courseName) { this.courseName= courseName;
[Code]...
The problem I'm having is, for the first part of the question where I need to automatically increase the array size. I'm really not great at this stuff. I have tried breaking it down, but can't "get it", I guess.
I assume, it'd be a loop that checks to see if the student array is full and if so, do the increaseArray() part, by maybe multiplying the student array and then assigning it. I just don't know how to do it haha.
My *best* attempt at the loop so far has been
if (students == students.length){ int bigArray = 2*students.length; String increaseArray()= new String[students]; System.arraycopy(students, 0, increaseArray, 0, students.length); students= increaseArray;
I am having trouble with an assignment. I need the user to input the size of the array and print when asked. In my program, it prints 100 numbers instead of the user input number, such as 15.
import java.util.Arrays; import java.util.Scanner; import java.util.Random; public class Lab9 { public static void main(String[] args) { Scanner scan = new Scanner(System.in); int [] values = new int [100];
I am trying to make a code that copies the users String to a char array. However, I am in a predicament: since I would not know the exact size of the users String I am left with the options of either making my array large by default, filled in with, lets say 25, empty spaces per index OR starting out with a default size of 1, with an empty space, and then some how increase the size from there.
At this moment I am leaning on the first option, creating a large default array and then deleting the unused values. However, this brings me to my actual question: if I set the non used indexes to null, if that wont give me an error, would that change the size of my array?
Ex: //lets say i finally copied all of the values and this is the result char[] word = {'b', 'o', 'b', ' ', ' '}; for(int i = word.length(); i > 0; i--){ if(word[i] == ' ')//delete the value so the size decreases word[i] = null;//if possible }
protected void randomise() { int[] copy = new int[]; // used to indicate if elements have been used boolean[] used = new boolean[array().length]; Arrays.fill(used,false); for (int index = 0; index < array().length {
I'm just putting together a little 'horse racing' program while I'm learning Java, and I have a class called Race that creates an array list of thorougbred horses called field, and asks the user to enter then names of the each horse in the field, with a maximum of 14 horses. The problem occurs with the current code that I have:
import java.util.*; public class Race { RaceHelper helper = new RaceHelper(); ArrayList<thoroughbred> field = new ArrayList<thoroughbred>(); public void setField() { //enter the horses in the race and determine the size of the field
[code]....
the statement of the index position and current size was for me, so I could see what was going on.What I don't understand is the while loop. not that the class doesn't compile and run (you can see that it does), it's the output. Why does the <= sign allow one more entry and increase the size of the field to 15?
Less than or equal to 14 should give a maximum field size of 14, right, With the starting object at index position at zero and going up to 13, for a total size of 14 thoroughbred objects if I just use while (field.size()<14) or a for loop, then the output is fine; it allows a max of 14 entries and prints the results. I thought it had something to do with the size being zero based, but that doesn't seem to matter -- unless it does matter and I'm missing it. why the comparison I'm using produces this output? a field of 14 horses shouldn't matter whether it's zero or 1 based, as long as the size of the field is 14, so why the extra entry with this while condition?
I'm working on a program to create a blackjack game using objects (one for card, deck. and hand). Withing my hand object I am trying to add cards to the hand but it is only adding the last card i try to add and giving null values for the the ones before.
class BlackJackHand { private BlackJackCard [] hand; public void addToHand(BlackJackCard c) { if (hand == null) { BlackJackCard [] tempHand = new BlackJackCard[1]; tempHand[0] = c; hand = tempHand;
[Code] ....
What I want this section to do is add cards to the current hand. I was intending for it the hand to be null at first and the if(hand == null) piece to add the card the first time and then the else piece would be used when the hand already has at leas one card. I want the else section to create a temporary array that is one larger than my current hand, copy the cards from the old hand to the new hand, and then add a new card to the last space before rewriting the old hand as what the temporary hand is.
The code I am using to test if the addToHand() is working is
class BlackJackTest { public static void main (String[]args) { BlackJackCard c1= new BlackJackCard(1,0); BlackJackCard c2= new BlackJackCard(1,4); BlackJackCard c3= new BlackJackCard(1,5); BlackJackHand h1 = new BlackJackHand();
[Code] .....
BlackJackCard has the parameters (int suit, int value)
This should print: ace of clubs 4 of clubs 5 of clubs
I'm currently trying to build a DAO based application where you use a text file as a data source. It have worked out well until I tried to delete lines from the file.
I've managed to fill out the temp file with everything except the line I wanted to remove, but when I try to replace the original file with the temp file it won't work. It casts the error: "temp.txt -> databilar.txt".
I've also tried to use the renameTo method without any success...
Write a program to create an integer array of size 20. Then, the program should generate and insert random integers between 1 and 5, inclusive into the array. Next, the program should print the array as output.
A tremor is defined as a point of movement to and fro. To simulate it, the program will generate a random number between 0 and 19, which represents the location in the array (i.e. index number). Then, the 3 numbers to the left and right of this location should be reset to the value 0. If there isn't 3 numbers to the left and right you may assume a lesser number depending on the boundaries of the array.
Then, the final array should be printed as output. There is no user input for this program.Your program must include, at least, the following methods:
-insertNumbers, which will take as input one integer array and store the random numbers in it. -createTremor, which will generate the random number as the location and return it.
I am trying to make a method that takes in a cmd command (nslookup, systeminfo, etc), and outputs the response to a text file. I have tried a dozen different ways with no success. below is my most current failure. It succeeds when i run it, but nothing shows up in the text file.
public static void runSystemCommand(String command) { command = "ping 192.168.1.3"; try{ Process proc = Runtime.getRuntime().exec(command); InputStream in = new BufferedInputStream(proc.getInputStream()); OutputStream out = new BufferedOutputStream(new FileOutputStream("C:NetPanelDataping.txt"));
I am having trouble with reading specific lines from a text file in to a JTextArea. I want it to read only the first line of my text file and print it out in my JTextArea, however nothing is printing out.
BufferedReader a = null; try { a = new BufferedReader (new FileReader ("D:/FinalProjectFile.txt")); a.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace();
First i want to read the text file and I want to count the number of occurrence of each item and after that i want store the result in hashmap structure...
I am trying to print a loop inside an array of a greater size than the loop itself. Like for example I have an array of size 7 but it has only 3 elements.
now what I want to do is print these three numbers in a loop so that my array[3]=2;array[4]=3;array[5]=4 ...... till the last one. Also the array could be any size and not just 7.
I am trying to create an array list without using the built in arrayList class that java has. I need to start the array being empty with a length of 5. I then add objects to the array. I want to check if the array is full and if not add a value to the next empty space. Once the array is full I then need to create a second array that starts empty and with the length of the first array + 1.
The contents of the first array are then copied into the new array without using the built in copy classes java has and then the new array ends up containing 5 elements and one null space the first time round. The first array is then overwritten with the new array containing the 5 elements and the null space. The process then starts again adding values until the array is full which will be 1 more value then recreating the second array empty and the length of the first array + 1. This is my attempt at creating this but I have run into multiple problems where I get only the last value I added and the rest of the values are null:
public class MyArrayList { public Object arrayList[]; public MyArrayList(Object[] arrayList) { this.arrayList = arrayList;
I am asked in my assignment to make a program that accepts a text file as an example a novel and i have to sort each word as a PERSON or ORGANIZATION or LOCATION or O as in Other , example :
Microsoft/ORGANIZATION ,/O Nelly/PERSON !/O '/O
Now we notice that microsoft is and organitzation and "," is Other and Nelly is a person's name and so on ..
Now I am asked to return the numbers of tags in the text which is 4 in our case because we have (ORGANIZATION,PERSON,LOCATION,OTHER)
My question here is my logic true ? And since i made a map of String,String ; Is there any way that i can get the size of the values in our case the values are the organization etc.. ?
I am just not sure of some theory in collections, ArrayList and LinkedList maximum capacity depends on the memory allocated to the JVM. But according to few people those list has a maximum capacity of Integer.MAX_VALUE.
According to my experiment, those list has a maximum capacity of Integer.MAX_VALUE since the get method of List accept a parameter of int primitive type (index of element), therefore we can conclude that the maximum capacity of List is equal to Integer.MAX_VALUE.
But what about the Map? get() method of map accepts object(the key of the map). So does it mean that the maximum capacity of Map depends on the memory allocated to our JVM? Or its maximum size is Integer.MAX_VALUE also just like Lists and Arrays? Is there a way to prove it? Is Map designed to hold infinite number of data (disregarding the heap memory space exception)?
And also about Stack, Deque? is it also the same as Map (in terms of maximum capacity)?
