Array / List Of Ints Contains Specific Number
Jan 24, 2014I've been trying to make a list of numbers/ints and later on check that list for a specific number.
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Get List / Map Or Array Of A Specific File Type Files In A Directory?
Sep 18, 2014If I specify the directory in file type or path string type how can I get a list of files that are file type .yml in that folder, so I can loop through and do something with each single file.yml in that specified directory.
View Replies View RelatedAccept Array Of Ints And Squares Each Element Of Array
May 13, 2014I need to write a method that accepts an array of ints and squares each element of the array. No creating new arrays and no returning any values.
public void squareInts(int[] ints) {
for(int i = 0; i < ints.length; i++) {
ints[i] = (ints[i] * ints[i]);
}
}
Count Number Of Occurrences Of A String In Array List?
Apr 6, 2015I am trying to count the number of occurrences of a string in an array list. I used the following code:
int count = Collections.frequency(strings, search);
strings is the name of the array list and search is the string that I am trying to count the number of occurrences of. My program compiles correctly, but when I enter the string to search for, I get the following error: "Exception in thread "main" java.lang.NullPointerException at java.util.Collections.frquency(Collections.java:37 18)
Why am I getting this error message and how do I fix it?
Creates Array Of 3 Consecutive Ints (0 - 7) User Has To Guess What Those Numbers Are
Aug 16, 2014I have the following program. In a nutshell, I creates an array of 3 consecutive ints and the user has to guess what those numbers are, knowing that they are between 0 and 7, this is from Head First Java. In the book, the code has a bug that is made on purpose and they challenge you to fix it. As you can see bellow, every time a user's guess matches a int in the array, the NumOfHits is increased by one. When the NumOfHits is 3 (the length of the array) the game finishes.
The bug is that if you guess 1 and 1 is in the array, if you type in 1, 3 times, I will increase the NumOfHits 3 times and end the game as if you had won. To solve the bug, you need to find a way to tell the program that if the user already guessed that number, it should no longer be taken into account and we shouldn't increase the NumOfHits if the same number is provided.
I "fixed" this by searching for the index of the number that matches an int of the array, and changing that index's value to 100, since the user knows that the numbers are between 0 and 7, they will not submit 100.
The result? If the user submits 2 and 2 is in the array, the value of its indexed is replaced by 100, so that if the user submits 2 again it doesn't count as a match.
Please see the comments in the code
import java.io.*;
import java.util.Arrays;
class DotCom{
int NumOfHits = 0;
int[] LocationCells;
public void setLocationCells(int[] locs){
LocationCells = locs;
[Code] .....
The code works, but for some reason, some times I get a ArrayIndexOutOfBoundsException run time error and it appears to be somehow random. This is what I saw on the command line earlier
C:Userspablo.alvarez>java launchDotCom
Enter a number: 3
missed
Enter a number: 4
hit
Enter a number: 5
hit
Enter a number: 7
missed
Enter a number: 5
missed
Enter a number: 4
missed
Enter a number: 3
missed
Enter a number: 4
missed
Enter a number: 5
missed
Enter a number: 6
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
at DotCom.checkYourSelf(launchDotCom.java:16)
at DotComGame.startGame(launchDotCom.java:59)
at launchDotCom.main(launchDotCom.java:72)
As you can see here, 3 returned 'missed' but 4 and 5 returned hit. Since the numbers are in sequence and are only 3, it makes sense that the last number is 6 (4,5,6). You will then notice that when I submitted 3 and 4 again it returned 'missed' as expected, because the numbers were already matched earlier, but then when I submitted 6, it returned the error seen above.
Sometimes this doesn't happen at all, sometimes it happens at the 2nd guess or third, it appears to be somehow random. I'm familiar with the error message, but I don't see where I'm using an index that doesn't exist in the array. The only time I'm referencing an array index is on
LocationCells[index] = 100;
but the index variable will only hold a value if the int submitted by the user matches on of the values in one of the indexes, so how is it that I'm going over the number of available indexes?
Updating Specific Value In Linked List
Feb 18, 2014I create and populate someLinkedList with '*' characters as soon as a gameLinkedList object is created, so my class is something like
private int size;
public class gameLinkedList{
private CharNode game;
public gameLinkedList(String someWord){
size=someWord.length();
for(int i=0;i<size;i++){CharNode aNode = new CharNode('p');
[Code] .....
How To Traverse Through Linked List And Remove Specific Element
Nov 12, 2014 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:
package llchallenge;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.Scanner;
[code]...
How To Traverse Through Linked List And Remove Specific Element
Nov 12, 2014This 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
[Code] ....
User Enter 5 Digit Number And In Return List Each Number On Their Respective Lines
Sep 16, 2014So I am currently writing my first assignment and have run into problems with my coding. The task was to have someone enter a 5 digit number and in return, I list each number on their respective lines. We also must create an error if a number other than 5 digits was entered. My problem is that when they enter a 1 or 2,3,4,6,7,8 digit number.. the error message occurs along with the rest of the messages (listing the numbers, etc). I want the program to end (or even re-ask to enter the numbers) if they incorrectly enter the data.
View Replies View RelatedSplitting Array By Specific Value
Jan 15, 2014How do you split an array by a specific value.
For instance this is my array: "4*6*9*89"
How can I take out "*" and therefore split up all the values like this: "4" "6" "9" "89"
Copy Specific Array Data?
Dec 4, 2014if there was a way to copy specific array info into a temp array with more concise code?
This is the code I have for instance:
tempList[0] = myCube.orange[2];
tempList[1] = myCube.orange[5];
tempList[2] = myCube.orange[8];
tempList[3] = myCube.blue[6];
tempList[4] = myCube.blue[7];
tempList[5] = myCube.blue[8];
But isn't there any way I could just condense it to be like:
tempList[0,1,2] = myCube.orange[2,5,8];
It would save me from 72 lines of code down to 24 if I could rock it all on one line.
How To Retrieve Index Of Specific Element In Array
Mar 3, 2015I'm trying to iterate through an array of integers and find the start position of the part of the array containing the most consecutive 1s.
For example given the array {1,3,1,1,1,1,5,3,2,1,1}, the method should return 2 and given {1,4,5,1,1,1,5,1} the method should return 3.
So far, I've managed to retrieve the element where the consecutive 1s begin. However, I'm unsure how to get the index of this element and this implementation doesn't work if there is more than one set of consecutive 1s.
public class GetIndex {
public static int getPosition(int[] myArray) {
int index = 0;
int tracker = 0;
int mostOnes = 0;
for(int i = 0; i < myArray.length; i++) {
[Code] .....
How To Index Array So That Specific Data Can Be Shown
Aug 5, 2014how to index the arrays so that i can choose specific data so that averages and maximum and minimum values can be worked out. My code is below
package weatherProgramPackage;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
[code]....
How To Randomly Assign Specific Values In Array Or ArrayList
Apr 3, 2015I'm trying to build a monopoly like game, and atm I'm trying to find way how to build the Community and Chance chest cards. so far, my logic is
1-create an ArrayList of cards with a given order
2-for a given number of times(for loop) generate 2 random numbers ,which will be the parameters for Collection.swap().
3-swap.
here's the code for the shuffler Button
shuffler.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
for(int i=0;i<shuffeledMessages.length;i++){
int randoma=(int)(Math.random()*4);
int randomb=(int)(Math.random()*4);
Collections.swap(myMessages,randoma,randomb);
}
}
});
For now things seem to work pretty ok, but I'm wondering if this is a good and efficient way to shuffle a card chest especially in case of large number of cards. plus, I'm not sure what would be a good loop count for effective shuffling, in my case I used i<arraylist.size
Array Of Specific Length Filled With Random Numbers
Feb 15, 2015I was inquiring about selecting random numbers from a Fibonacci array, the original post for which is here: Exiting a 'for' Loop Early. I have managed to achieve this with the following code:
System.out.println("Random numbers from the Fibonacci array");
for(int i = 0; i < limit; i++) //Limit is an 'int' of 15 & is set as the length of the Fib. array. I'm calling it for the Random array, too!!
{
Random dice = new Random();
int randomIndex = dice.nextInt(array.length); //The Fib. array was simply called 'array'!!
if (array[randomIndex] < 100)
{
System.out.print(array[randomIndex]+ " ");
}
}
When the code prints I get a random set of numbers which occur in the Fibonacci sequence preceding it. However, the actual length of this Random array also changes each time, and never more than the limit of 15 specified in the 'for' loop. What I want to try and do is print the Random array with a specific length each time. I've tried changing the conditional statement of the 'for' loop in different ways to set the Random array's length, but had no luck.
Write A Specific Byte Sequence To A Specific Memory Location On A Removable Storage Drive?
Jan 29, 2014I am trying to write a specific byte sequence to a specific memory location on a removable storage drive. Does Java allow me a way to do this? I know the dangers in accessing memory, but the memory location of the data that will be written will never change.
how to assign a variable a memory location.
Swing/AWT/SWT :: Move Focus From Specific Jcombobox To Specific Jtextarea?
Nov 5, 2014How do I move focus from a jcombobox to a specific component say a jtextarea.
My attempt below seems to be moving to a random component not the desired jtextarea.
takenByCombo.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_TAB ) {
e.consume();
dayJTArea.requestFocus(); // focust not moving dayJTArea
}
}
});
I applied the above logic to move focus from a specific jtextarea to another jtextarea as seen below and it works as desired.
dayJTArea.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_TAB ) {
e.consume();
monthJTArea.requestFocus();
}
}
});
Changing Value In Specific Point Of Specific Line In TXT File
Feb 9, 2015So here we go with my problem:
- from the main class will arrive three variable (String name_used, int level_choose, int level_result)
I have a .txt file with this kind of formatting:
mario 1 1 0 1 0 1
carlo 0 0 0 1 1 0
...
Where I use 1 and 0 in the main for write if the level (you see that the numbers are always sixr? are egual to six level existing) BEFORE is done correct or wrong
- when in the main a user make a level a feedback coming back from the class level saying if the user made the count correctly or wrong. and i wanna replace the value (1 or 0) in the txt file with the new level result.
So i have all what i need as parameters i think.
name_used to look for the correct line in .txt file with .indexOf
level_choosed to go throught the correct index of that line
level_result (1 or 2) to be replaced with the existing one
Java Code:
public void salvaRisultati(String name_used, int level_choosed, int result_of_level) throws FileNotFoundException{
}
} mh_sh_highlight_all('java');
Check Specific Value From A Specific Line From TXT File
Feb 8, 2015I have some problem to understand the way to make this:
In my main class a user can save his name in a txt file (and the system initially will add 6 value equals to 0) than he can choose between 6 level and make it.
example of .txt file data:
mario 0 0 0 0 0 0
carl 0 0 0 0 0 0
AT THIS MOMENT i just made other class and they work, is this new one that is hard for me. I'm trying to make a class that:
1- (first method called verificaRisultati) take name_used and level_choosed from the main and go to check in the .txt file if that level before was done right(1) or wrong(0)
and return something like "before you made this level properly" or "before you made this level incorrectly" AND THEN let the user start with the level.
2- (second method called salvaRisultati) at the end of the level i wanna pass the result (correct/incorrect) to another method of this class that will save the value (1 or 0) associated to the user in the right position.
This is the class that i'm writing:
Java Code:
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
public class ResultUsers {
[Code] ....
I really need some hint and some code example because I'm stuck. How I can take exactly the line with the user name? How I can correctly split the line in an array and then read/modify the value for that level?
List Prime Number From N To M
Oct 15, 2014I am trying to list of prime number from n to m but my program give only one number
import java.io.PrintStream;
import java.util.Scanner;
public class Check05B
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
PrintStream output = System.out;
output.print("Enter a number to test: ");
[Code] ....
Cannot Set Ints From Constructor
Aug 10, 2014Java Code:
package ZooZ;
import java.util.Random;
public class Animal {
int playerOne; <------- Remains 0
int playerTwo; <------- Remains 0
Random random = new Random();
[Code] ....
If you look at the code, I set "playerOne" and "playerTwo", to set them as what was passed in from another class..
In the Animal constructor.
in that constructor the value is 2. But when I use it in the "Bash()" method it is 0 in the console.
Why doesnt the playerOne and playerTwo stay the value it is assigned in the constructor.??
Changing Ints From Another Class
Jun 27, 2014I am making a simple text based game and i have a monster, and I am tring to make its health go down whent he user input "s" but istead it doesnt change and the users health even goes up.
Main.java
package exodus.game.main;
import java.util.Scanner;
import exodus.game.monsters.Nirav;
public class Main {
static String name;
static String inputtemp;
[Code] .....
String To Ints Separated By Comma?
Feb 5, 2014public Date(String s) {
???????
}
such that
Date("1250/345/759")
it will return
(1250,345,759)
in short Date("a/b/c")
return (a,b,c)
Subtracting Strings - Parsing Two Values To Ints
Nov 5, 2014I have started learning Java and have some across some difficulties. I'm trying to subtract two strings.
for example, with these strings;"032"&&"100". I want to be able to subtract each number individually so that the answer would be "032". 0-1;3-0;2-0;. if i get a negative number, the number would be zero. hence, the 0-1 staying zero in the answer.
I have tried using substring, and parsing the two values to ints, but don't know what to do next. I have also tries using a for loop, to go through each arrays of the strings. I am not allowed to use StringBuilder and I need to return "032".
Here's what i've done so far:
public static String appliquerCoup( String combination, String coup ) {
String nouveauCoup="";
if(combination!=null&&coup!=null){
for(int i=0;i>combinaison.length();i++){
[Code] ....
Calculating Average Of Two Ints And Converting To A Double
Oct 31, 2014I have been asked to construct an application that will read in the exam mark and coursework mark and then print out to 1 decimal place the average of the coursework and exam mark. When I submit it it says it's incorrect.
class Main
{
public static void main( String args[] )
{
int ExamMark=71;
int CourseworkMark=40;
double mark = (double)(ExamMark + CourseworkMark) / 2;
[Code] ....
Create 2D Array Out Of CSV File And Find Number Of Elements To Determine Array Size
Mar 24, 2015I 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];
[Code] ....