I have an array that I filled with 30 random characters, but now I am trying to sort them in ascending order and the descending order using lambda expressions.
public class RandomCharacters {
public static void main(String args[]){
Random r =new Random();
char myarray[] = new char [30];
for (int i = 0 ; i < 30; i++)
[Code] ......
I have the following structure and want to use lambda expressions with it, but an exception occurs:
class SuperClass // (package private)
public class SubClass extends SuperClass // in same package as SuperClass
I have a functional interface (a listener), which has one argument of type SubClass.
public interface MyListener() {
void myMethod(SubClass e);
}
When I use the old-school Java 7 style:
addListener(new MyListener() {
@Override
public void myMethod(SubClass e) {
System.out.println(e);
}
});
Everything works fine! If I use Java 8 lambda expression instead:
addListener(e -> {
System.out.println(e);
});
It will throw an exception:
java.lang.IllegalAccessError: tried to access class SuperClass
I have this very annoying issue with Eclipse (I have the latest version installed). For some reason, every time I use the "default" keyword in an interface, it gives me an error similar to "Syntax error on token default", I deleted the "default" keyword, the error is gone. The same thing happens with "Lambda expression as well", say I have this object like this :
Actions myActions = () -> {System.out.print("Blah blah blah");}; ,
Eclipse also displays the error message similar to "Method body expected after (), delete '->' ". I checked the Java version I have, it is the latest one also ....
How to input 10 integer elements in an array & sort them in desc. order using the bubble sort technique.
View Replies View RelatedOne of the random number generators in Java extract the higher-order bits of the random number in order to get a longer period.
I'm not sure if I understand how this is done. Suppose that the random number r = 0000 1100 1000 1101. If we extract the 16 most significant bits from r; is the new number r = 0000 1100 or r = 0000 1100 0000 0000?
I'm trying to make the basis of a complex (pseudo)random password generator, but instead of 4 chars it is printing a 3 digit number.
public class PasswordGen {
public static void main (String[] args) {
char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();
int w = (int) ((Math.random() * 25 +1)); // pick a letter of the alphabet
[Code] ....
I need to put my scores in ascending order how do i do that?
public static void main(String[] args) {
char[][] answers = {
{'A', 'B', 'A', 'C', 'C', 'D', 'E', 'E', 'A', 'D'},
{'D', 'B', 'A', 'B', 'C', 'A', 'E', 'E', 'A', 'D'},
{'E', 'D', 'D', 'A', 'C', 'B', 'E', 'E', 'A', 'D'},
{'C', 'B', 'A', 'E', 'D', 'C', 'E', 'E', 'A', 'D'},
[Code] ....
I'm doing an exercise we're you're supposed to sort strings in alphabetical order, without importing anything , not using the Arrays.sort() method.
I think I got the method down partially right, or it is on the right track, but it is completely not being applied to my answer. All it prints out in the console is the actual String array twice, without sorting anything.
public class arrayofstrings {
public static void sort(String[] a) {
String temp= "";
int min;
int i= 0;
for (int j=0; j<a.length-1; j++) {
[Code] ....
I am trying to sort the 5 cards in decreasing order and this is exactly what my professor gave us but it has errors.
int pos;
int max;
for (pos = 0; pos < hand.length; pos++){
max = pos;
for (int i = pos + 1; i < hand.length; i++){
if (hand[max] < hand[i]){
max = i;
}
}
if (max != pos){
int temp = hand[pos];
hand[pos] = hand[max];
hand[max] = temp;
}
}
}
Line 6 has an error with the < operator.
Line 11&13 says cannot convert from card to Int.
This method is passing in Card[] hand
Here is the java code that i compiled on eclipse but each time i run it i am getting different sequence of output !!
What I did is that my main() calls a function m1() which calls a function m2() which throws an exception back to m1() which throws exception back to main().
public class ClassB {
public static void main(String[] args) {
try {
m1();
} catch (Exception ex) {
ex.printStackTrace();
[Code] ....
The output is as shown in screenshots at different times :
SCREENSHOT 1:
SCREENSHOT 2:
SCREENSHOT 3:
How is this possible ??
How do i make this merge sort take on random numbers in an array instead of hard coding the numbers
Integer [] a = {8, 2, 6, 7, 5, 4, 3, 1};
mergeSort(a);
System.out.println(Arrays.toString(a));
}
public static void mergeSort (Comparable [] a){
[code]....
Java Code:
import java.util.ArrayList;
import java.util.Random;
public class NumSorting {
public static int numOfComps = 0,
numOfSwaps = 0;
public static void main(String[] args)
[Code] ....
What is wrong with my code in this sorting program? It won't copy the random generated numbers to the sort method. How to get the random generated numbers to copy to the sort method. Below is what the program is displaying.
Original order : 3 2 5 4 1
Selection Sort
Original order:
[I@7a84e4
Number of comps = 10
Number of swaps = 0
Sorted order : 0 0 0 0 0
I have been assigned to write a program that has a user input random numbers then the program is to sort them in different ways. I have the coding for the different sorts but, I have an error saying that I am missing a return statement in the "Bubble" method. I am trying to return "arr[i]" in the "for loop" which gives me this error, and when I try to take the "return arr[i]" outside of the "for()" loop the error reads the it cannot locate variable "i".
import java.awt.* ;
import java.awt.event.*;
import javax.swing.*;
public class SwingSorts extends JFrame implements ActionListener
{
JRadioButton bubble;
JRadioButton selection;
[Code] .....
i am working on the same project and i got the code to make them print going down but not sideways.
public class ArrayofHope
{
public static void main(String args[])
{
System.out.println("Decimal Character
");
for(int j = 65; j <= 90; j++)
{
System.out.print(j);
System.out.println(" " + (char)j); //Character
}
}
}
I have an array of Strings, one on each line and I need to convert them into an array of char's.
For Example:
This
is
an
Example
of
what
my
input
is.
In order to accomplish that I did the following-
String[] lotsOfText = a.gettingAnArrayAsAReturn();
char [][] myCharArray = new char [lotsOfText.length] [lotsOfText.length];
for(int i=0; i<lotsOfText.length; i++){
for(int j=0;j<lotsOfText[i].length();j++){
myCharArray[i][j] = lotsOfText[j].charAt(j); }}
But whenever I try this and then try to print the output :
for (int i = 0; i < lotsOfText.length; i++) {
for (int j = 0; j < lotsOfText[i].length(); j++) {
System.out.print(myCharArray[i][j]);
}
}
I get nothing. I'm not sure what's the flaw in my logic, is it the char array initialization that's wrong or is it something else ?
I will write guess the picture game. I didn't find for example 4*4 picture how to sort picture random everytime ?
For example , when game start random various are 2734856127348561 two times same picture...
Goal this time is to take a charArray, copy it into another charArray while reversing the things in it.
E.g. charArray["!ollaH"] into charArrayNew["Hallo!"]
My first idea was to revert the stuff in the Array with a ! cause i saw earlier that u can work with that too revert booleans. Sadly i didnt happen to make it work.
Next thing i thought of was a for loop to go trough the charArray and copy every section into charArrayNew just at the opposite end.
Java Code:
import java.util.Arrays;
public class aufgabe43 {
public static void main(String[] asgr){
char[] charArray
[Code] .....
Eclipse doesn't show any errors, and as u told me last time i did include import java.util.Arrays; to output the array in the end.
When i try to compile the code eclipse returns with an error
Java Code:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 68
at aufgabe43.main(aufgabe43.java:8) mh_sh_highlight_all('java');
Which I frankly don't understand since the array . Length is exactly the same.
So I am working on a project for my Java course and for whatever reason, I am absolutely struggling with this assignment. I've made some progress but I can't seem to completely wrap my head around the algorithm I'm being told to use. I feel that everything is correct up to a particular point.I believe I am having issues moving a char array into a char matrix.
package edu.cofc.csci221.ui;
import java.lang.*;
public class Decoder
{
private int[][] M;
[code]...
Would I just need to loop through lsb one at a time and assign them to sequential spots within D? Basically call my get binary value and such in the outer loop and then use the inner to loop through both arrays and reassign values?
I'm trying to take the information from one 2d char array and put it into another char array but instead of traversing the array left to right I want the new array to be top to bottom.
Example fg would be fh
hi gi
I'm having trouble getting the information from one to the other.
[code]public static char[][] translateIt(char[][] english){
int rows = english.length;
int columns = english[0].length;
char[][] chinese = new char[columns][rows];
for(int j=0; j < columns; j++){
for (int i = 0; i < rows; i++){
//chinese[i][j] = english; this is commented out because it didn't work.
}//Ending bracket of columns for loop
}//Ending bracket of rows for loop
return chinese;
}//Ending bracket of translateIt[code]
How can I display this result.aJohny
I have array contain numberi create new char array and i want to check if a number is >= 90 in array then input A at the same index in char arraythen second part i want to check if char array contain "A" then a = a + 1.
The result is like this:
A: 5
B: 29
C: 38
D: 24
E: 12
F: 17
public class Test {
public static char[] grades(int[] getMarks) {
char[] grade = new char[getMarks.length];
for (int i = 0; i < getMarks.length; i++) {
if (getMarks[i] >= 90) {
[Code] .....
I have a string array but each cell in the 1d string array stores each character the text file is :
"START START START
The quick brown fox jumps over the lazy dog 1234567890-= !"$%^&*()_+ QWERTYUIOP{}ASDFGHJKL:@~|ZXCVBNM<><? /.,mnbvcxzasdfghjkkl;'#][poiuytrewq789654123.0
+-*/``""$% hello this is a test file using all the characters availible on the keyboard for input END END END END"
so in the string it is:[0] = S, [1]=A, [2]=R ...ect along the text basically i need to convert each character in each cell of the 1d string array to its hesidecimal value..i have created my own method which will take in a char and return a string containing the charcters hex value.
public static String toHex(char c) {
char char2ascii = c;
int i = 0;
int num = (int) char2ascii;
String hex ="";
[code]...
what i want to do is run each cell through the toHex method so i eventually have a string array containing the hex value of each character in my text.
example..i want:
String[] hexarray = S, T, A, R, T
a run it through my method to convert to hex then it will become
String[] hexarray = 53, 54, 41, 52, 54
Im not allowed to use inbuilt libarys and classes to do the hex conversion thats why i have my own method for it .
I am learning about Lambdas and am having a little difficulty in a conversion. I need to introduce a List into which the array supplied by the values method of the Field class is copied, using the asList method of the class Arrays. Then I need to convert the for loop with a forEach internal loop using a lambda expression as its parameter. The body of the lambda expression will be the code that is the present body of the for loop. I believe I have the List syntax correct ( List<String> list = Arrays.asList(data); ), but I am having a hard time on figuring out what to do with the for loop, or even where to start with it.
public AreaData(String... data) {
List<String> list = Arrays.asList(data);
/* Assert to check that the data is of the expected number of items. */
assert data.length == Field.values().length : "Incorrect number of fields";
for( Field field : Field.values() )
[Code] .....
I am relatively new to java, and i am trying to create a window inside of a 2d char array, and eventually i will have to draw other shapes in this window. so for example
* * * * * * * * *
* *
* *
* *
* *
* *
* *
* *
* * * * * * * * *
The problem is my window is not drawing correctly too the border, but a couple extra chars on the x columns. Here is code. The dimensions of the window will eventually be passed through scanner in main, if i ever work out how to even draw it.Also, in class we never learnt to use the Graphics class, so im pretty sure we are not supposed to use it.
public class Window
{ //default values
private int xRow;
private int yCol;
private char ch;
public char[][] windowz = new char[30][20]; //30,20 (yx)flat values cuz doesnt work
[code]....
Example code that works:
Java Code: List<String> list = Arrays.asList(strDays); mh_sh_highlight_all('java');
My code that doesn't work:
Java Code: List<char> list = Arrays.asList(userInputChars); mh_sh_highlight_all('java');
Error that I get:
Assignment6_2.java.java:45: error: unexpected type
List<char> list = Arrays.asList(userInputChars);
^
required: reference
found: char
1 error
The entire program (that works, except for the error above):
Java Code:
import java.util.Collections;
import java.util.List;
import java.util.Arrays;
import java.util.Scanner;
class Assignment6_2 {
public static void main(String[] args) {
[Code] .....
I'm trying to find a word in an array of char.....but I'm stuck. How to formulate the code to step through the array and pick out the word. This is what I have so far...
public static void searchAcross(String string, char[][] puzzle) {
// Gets the number of rows in the matrix
int rowLength = puzzle.length;
//Gets the number of columns in the matrix.
int colLength = puzzle[0].length;
[Code] ....
I'm trying to convert all letters in a 2D char array into number. As results, I want a = 0, b=1, c=2, ... z=25.
Then, I tried this as part of my code:
char [][] letters = {{'i', 'u'}, {'a', 'g'}, {'e', 'k'}};
for (int i = 0; i < letters.length; i++) {
for (int j = 0; j < letters[i].length; j++) {
if (letters[i][j] >= 'a' && letters[i][j] <= 'z') {
letters[i][j] = (char) ((letters[i][j] - 'a') + '0');
}
}
}
The result of my code is not what I expected before.
From 'a' to 'j', it worked well. But, from 'k' until 'z' it didn't print expected number.
What's wrong with my code and what is the correct way to fix it?