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The program don’t seem to work if there is a duplicate number in the array

If the user searches a number within the array, the system should print out the index that the number is located, if not it would print out search not found. As of now, it works only if there are no duplicate numbers in the array.
I tried removing the break but that would stop the program from printing the second index that also contains the search number.
Any help would be greatly appreciated, thank you!
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int[] array = new int[10];
array[0] = 6;
array[1] = 2;
array[2] = 8;
array[3] = 1;
array[4] = 3;
array[5] = 0;
array[6] = 9;
array[7] = 8;
System.out.print("Search for? ");
int searching = Integer.valueOf(scanner.nextLine());
for (int i = 0; i < array.length; i++) {
int input = array[i];
if (searching == input) {
System.out.println(searching + " is at index " + i);
break;
}
else if (searching != array[i] && i == (array.length - 1))
{
System.out.println(searching+" was not found!");
break;
}
}
}

Scanner scanner = new Scanner(System.in);
int[] array = {6,2,8,1,3,0,9,8};
System.out.print("Search for? ");
int searching = scanner.nextInt();
ArrayList positions=new ArrayList();
for (int i = 0; i < array.length; i++) {
int input = array[i];
if (searching == input) {
positions.add(i);
}
}
if(positions.size()>0) {
for(int x=0;x<positions.size();x++) {
System.out.println(searching+" is at index "+ positions.get(x));
}
}
else {
System.out.println(searching+" was not found!");
}
To receive an int with a scanner it is easier to use the nextInt () method. In the first for you can accumulate the positions where the number that is searched for in an arraylist matches, then you check that the arraylist is not empty and you print all the positions in which the number has been found. If the list is empty, the message of not found is printed.

Need to find out the duplicate element in array without using Hashmaps

I am a newbie here. I wanted to print out the duplicate elements in an array.
This code will print out the duplicate elements.
Suppose I'm taking an array of size 5 with elements [1,2,5,5,5]
This code will print:
Duplicate elements: 5,5,5 //(since 5 is being repeated thrice.)
But I want the output something like this
Duplicate Elements: 5 //( instead of printing 5 thrice)
import java.util.*;
import java.util.Scanner;
public class duplicateArray{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
System.out.print("Enter the size of the array: ");
int x =sc.nextInt();
int arr[]=new int[x];
int i,count=0;
for(i=0;i<x;i++){
arr[i]=sc.nextInt();
}
System.out.print("Array: ");
for(i=0;i<x;i++){
System.out.print(arr[i]+" ");
}
System.out.println(" ");
System.out.print("Duplicate elements: ");
for(i=0;i<arr.length;i++){
for(int j=i+1;j<arr.length;j++){
if(arr[i]==arr[j]){
System.out.print(arr[j]+" ");
}
}
}
}
}

The following code does it without creating any additional data structure. For each element, it counts the number of duplicates previously encountered and only prints the first duplicate.
If I were doing this in the real world, I would use a Set but I'm assuming you haven't learnt about them yet, so I'm only using the array that you've already created.
import java.util.Scanner;
public class DuplicateArray {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter the size of the array: ");
int x = sc.nextInt();
int[] arr = new int[x];
System.out.print("Enter " + x + " values: ");
for (int i = 0; i < x; i++) {
arr[i] = sc.nextInt();
}
System.out.print("Array: ");
for (int i = 0; i < x; i++) {
System.out.print(arr[i]+" ");
}
System.out.println();
System.out.print("Duplicate elements:");
for (int i = 0; i < arr.length; i++) {
int numDups = 0;
for (int j = 0; j < i; j++) {
if (arr[i] == arr[j]) {
numDups++;
}
}
if (numDups == 1) {
System.out.print(" " + arr[i]);
}
}
System.out.println();
}
}

One solution is to create a separate List to store any duplicates found.
That, in addition to using the .contains() method of the List, you can ensure only one entry per int is made.
public static void main(String[] args) {
// Sample array of ints
int[] ints = {1, 1, 4, 5, 2, 34, 7, 5, 3};
// Create a separate List to hold duplicated values
List<Integer> duplicates = new ArrayList<>();
// Find duplicates
for (int i = 0; i < ints.length; i++) {
for (int j = 0; j < ints.length; j++) {
if (ints[i] == ints[j] && // Are the ints the same value?
i != j && // Ignore if we're looking at the same index
!duplicates.contains(ints[i])) { // Check if our List of duplicates already has this entry
duplicates.add(ints[i]); // Add to list of duplicates
}
}
}
System.out.println("Duplicates: " + duplicates);
}
Output:
Duplicates: [1, 5]

This is pretty simple however you need to sort array before. All you need to know if duplicate for an element exists or not and do the printing in the outside for loop. Rest is described in comments
Arrays.sort(arr); // Sort Array
for (int i = 0; i < arr.length; i++) {
boolean hasDuplicate = false; // Assume that arr[i] is not repeating
for (int j = i + 1; j < arr.length; j++) {
// Check if it is repeating
if (arr[i] == arr[j]) {
// If it repeats
hasDuplicate = true;
}
// Since array is sorted we know that there is no value of arr[i] after this
if (arr[i] != arr[j]) {
// Set i to the last occurrence of arr[i] value
i = j - 1;
break; // Since there no occurrence of arr[i] value there is no need to continue
}
}
// Print the element at i
if (hasDuplicate)
System.out.print(arr[i] + " ");
// In next iteration loop will start from the index next to the last occurrence of value of arr[i]
}

System.out.println("Duplicate Elements : ");
for(int i = 0; i<arr.length; i++){
boolean isDuplicate = false;
for(int k=0;k<i;k++){
if(arr[i]== arr[k]){
isDuplicate = true;
break;
}
}
if(isDuplicate){
continue;
}
int count = 0;
for(int j=0; j<arr.length; j++){
if(arr[i] == arr[j]){
count++;
}
if(count >1){
System.out.println(arr[i]);
break;
}
}
}

Without using Hashmaps, I think your best option would be to first sort the array and then count the duplicates. Since the array is now in order you can print the duplicates after each number switch!
If this is for an assignment go ahead and google bubble sort and implement it as a method.

10 element Array will only accept 5 integers during Selection sort project

Ok, so this is for a Java class, but I'm not looking for someone to write the code, just help me debug this one. I want to enter 10 integers and have the inputs sorted in ascending order as they are entered then displayed, without any zeros (0) that may exist in the array.
Example of what the assignment should look like:
Enter 10 integers - one at a time...
Enter integer #1: 21
Sorted numbers: 21
Enter integer #2: 48
Sorted numbers: 21 48
Enter integer #3: 37
Sorted numbers: 21 37 48
etc....
I have tried a Selection Sort, Insertion and Bubble Sort, but the array will not hold or display more than 5 numbers.
Help.
Here is my Main:
import java.util.*;
public class Main {
static Scanner input = new Scanner(System.in);
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner (System.in);
int j = 1;
int[] list = new int[10];
System.out.println("Enter 10 integers - one at a time...");
for (int i = 0; i < list.length; i++){
System.out.print("Enter integer #" + j + ": ");
list[i] = input.nextInt();
j++;
//SortMethod.sort(list, list.length);
SelectionSort.sort(list);
//BubbleSort.sort(list);
System.out.print("Sorted numbers: ");
for(int p= 0; p<list.length; p++){
if (list[p] !=0)
System.out.print(list[p] + " ");
}
System.out.print("\n");
}
System.out.println("Done!");
}
}
Here is my Selection Sort:
public class SelectionSort {
public static void sort (int[] list){
for(int i=0; i<list.length; i++)
{
for(int j=i+1; j<list.length; j++)
{
if(list[i] > list[j] )
{
int temp = list[j];
list[j] = list[i];
list[i] = temp;
}
}
}
}
}
Thanks in advance!

Why don't you use List insteed of array and ready-to-go sorting implementations from jdk -> Collections.sort() ?
Anyway the problem is that you are inserting new integers into already sorted array and that causes disfunction of your code. So as you inserting new elements on indexes 0,1,2,3,4 - sorting algorithm moves them to positions 5,6,7,8,9. From this point your inputs starts overriding sorted values with new ones from input - (Main loop i>=5).All in all, it accepted 10 integers, but 5 of them where kindly overriten.
Here is little modified version of your work whitch works like you want. Analyze it!
import java.util.*;
public class test {
static Scanner input = new Scanner(System.in);
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
int j = 1;
int[] list = new int[11];
System.out.println("Enter 10 integers - one at a time...");
for (int i = 0; i < list.length - 1; i++) {
System.out.print("Enter integer #" + j + ": ");
list[0] = input.nextInt();
j++;
//SortMethod.sort(list, list.length);
SelectionSort.sort(list);
//BubbleSort.sort(list);
System.out.print("Sorted numbers: ");
for (int p = 1; p < list.length; p++) {
if (list[p] != 0)
System.out.print(list[p] + " ");
}
System.out.print("\n");
}
System.out.println("Done!");
}
}
class SelectionSort {
public static void sort(int[] list) {
for (int i = 0; i < list.length; i++) {
for (int j = i + 1; j < list.length; j++) {
if (list[i] > list[j]) {
int temp = list[j];
list[j] = list[i];
list[i] = temp;
i--;
break;
}
}
}
}
}

You are replacing sorted value with list[i] = input.nextInt(); with every input. So, 5 values always 0 in list. Use List<Integer> instead of int[] and add new value to List<Integer>. Try following code:
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner (System.in);
int j = 1;
List<Integer> list = new ArrayList<>();
System.out.println("Enter 10 integers - one at a time...");
for (int i = 0; i < 10; i++){
System.out.print("Enter integer #" + j + ": ");
list.add(input.nextInt());
j++;
//SortMethod.sort(list, list.length);
// SelectionSort.sort(list);
Collections.sort(list);
//BubbleSort.sort(list);
System.out.print("Sorted numbers: ");
for(int p= 0; p<list.size(); p++){
if (list.get(p) !=0)
System.out.print(list.get(p) + " ");
}
System.out.print("\n");
}
System.out.println("Done!");
}

I just modified the lines below the comments I put (temp declaration and for loop).
This changes makes program support negative numbers too, read the comments below:
import java.util.*;
public class test {
static Scanner input = new Scanner(System.in);
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
int j = 1;
int[] list = new int[11];
System.out.println("Enter 10 integers - one at a time...");
for (int i = 0; i < list.length - 1; i++) {
System.out.print("Enter integer #" + j + ": ");
// Add temporal variable to store input
int temp = input.nextInt();
// Check for empty place in list (as far as it seems you don't care about zeros)
for (int p = 0; p < list.length; p++) {
if (list[p] == 0) {
list[p] = temp;
break;
}
}
j++;
//SortMethod.sort(list, list.length);
SelectionSort.sort(list);
//BubbleSort.sort(list);
System.out.print("Sorted numbers: ");
for (int p = 1; p < list.length; p++) {
if (list[p] != 0)
System.out.print(list[p] + " ");
}
System.out.print("\n");
}
System.out.println("Done!");
}
}

Java: Unable to get Median calculated with code

I have two files that I am using for my Array median code. The first file( ArrayMedian.java) is used to collect and then calculate the median, the second file is the tester file ( ArrayMedianTest.java)
I was supplied with some source code and needed to modify it accept a set range for each number in the dataset. I got that part done and the random range displays, but now when I get to he array it no longer calculates, I really can't put my finger on what is going wrong.
Another thing I am trying to do is in the ArrayMedian, is put a while loop in there to make it terminate if a '0' is input for the dataset, but it does not seem to want to work in that file, could it be due to no main in the file?
package bonus2.u06.exercise.ex3;
import java.util.Scanner;
public class ArrayMedian {
private int[] arr; // just declare array
Scanner keyboard; // shared field
// initialize keyboard and array
public void init() {
keyboard = new Scanner( System.in );
System.out.print("Enter the dataset size: ");
int size = keyboard.nextInt(); // must be odd number
arr = new int[ size ]; // instantiate
}
// Randomize the array
public void getRange() {
//System.out.println("\nYou entered: ");
System.out.print("Enter a Range: ");
int range = keyboard.nextInt();
System.out.print("array: \n");
for(int i = 0; i < arr.length; i++){
int myRnd = (int)( range * Math.random() );
System.out.print(" " + myRnd + " ");
}
}
// find the median of array
public int calcMedian() {
int half_length = arr.length/2;
for (int i = 0; i < arr.length; i++) {
int count = 0;
for (int j = 0; j < arr.length; j++) {
if (arr[i] > arr[j])
count++;
}
if (count == half_length) {
//<========= terminate this method
return arr[i];
}
}
return 0;
}
}
ArrayMedianTest:
package bonus2.u06.exercise.ex3;
public class ArrayMedianTest {
public static void main(String args[]) {
// instantiate
ArrayMedian obj = new ArrayMedian();
// execute all methods
obj.init();
obj.getRange();
int median = obj.calcMedian();
System.out.println("\nmedian : " + median);
System.out.println("\n--- done ---");
}
}

Turn out, your algorithm works perfectly fine, except in the getRange() method, you forgot to set the values of the array, so the array is an array of zeros. Here is how it should look:
public void getRange() {
//System.out.println("\nYou entered: ");
System.out.print("Enter a Range: ");
int range = keyboard.nextInt();
System.out.print("array: \n");
for(int i = 0; i < arr.length; i++){
int myRnd = (int)( range * Math.random() );
System.out.print(" " + myRnd + " ");
arr[i] = myRnd; // <-- You missed this line right here!
}
}
Also, as a recomendation, if you want to put code in stackoverflow, it has to have a spacing of four at the begining of the line plus any indenting you might use. Good luck programming!

Taking User Input for an Array

A link to the assignment:
http://i.imgur.com/fc86hG9.png
I'm having a bit of trouble discerning how to take a series of numbers and apply them to an array without a loop. Not only that, but I'm having a bit of trouble comparing them. What I have written so far is:
import java.util.Scanner;
public class Lottery {
public static void main(String[] args) {
int userInputs[] = new int[5];
int lotteryNumbers [] = new int[5];
int matchedNumbers =0;
char repeatLottery = '\0';
Scanner in = new Scanner (System.in);
do{
System.out.println("Enter your 5 single-digit lottery numbers.\n (Use the spacebar to separate digits): ");
for(int i = 0; i <5; i++ )
userInputs[i] = in.nextInt();
System.out.println("Your inputs: ");
printArray(userInputs);
System.out.println("\nLottery Numbers: ");
readIn(lotteryNumbers);
for(int i=0; i<5; i++) {
System.out.print(lotteryNumbers[i] + " ");
}
matchedNumbers = compareArr(userInputs, lotteryNumbers);
System.out.println("\n\nYou matched " + matchedNumbers + " numbers");
System.out.println("\nDo you wish to play again?(Enter Y or N): ");
repeatLottery = in.next().charAt(0);
}
while (repeatLottery == 'Y' || repeatLottery == 'y');
}
public static void printArray(int arr[]){
int n = arr.length;
for (int i = 0; i < n; i++) {
System.out.print(arr[i] + " ");
}
}
public static void readIn(int[] List) {
for(int j=0; j<List.length; j++) {
List[j] = (int) (Math.random()*10);
}
}
public static int compareArr (int[] list1, int[] list2) {
int same = 0;
for (int i = 0; i <= list1.length-1; i++) {
for(int j = 0; j <= list2.length-1; j++) {
if (list1[i] == list2[j]) {
same++;
}
}
}
return same;
}
}
As you'll notice, I commented out the input line because I'm not quite sure how to handle it. If I have them in an array, I should be able to compare them fairly easily I think. This is our first assignment handling arrays, and I think it seems a bit in-depth for only having one class-period on it; So, please forgive my ignorance. :P
Edit:
I added a new method at the end to compare the digits, but the problem is it compares them in-general and not from position to position. That seems to be the major issue now.

your question isn't 100% clear but i will try my best.
1- i don't see any problems with reading input from user
int[] userInput = new int[5]; // maybe here you had a mistake
int[] lotterryArray = new int[5]; // and here you were declaring your arrays in a wrong way
Scanner scanner = new Scanner(system.in);
for ( int i = 0 ; i < 5 ; i++)
{
userInput[i] = scanner.nextInt();
} // this will populate your array try to print it to make sure
Edit : important in the link you shared about the assignment the compare need to check the value and location so if there are two 5 one in input one in loterry array they need to be in the same location check the assignment again
// to compare
int result = 0 ; // this will be the number of matched digits
for ( int i = 0 ; i < 5 ; i++)
{
if ( userInput[i] == loterryArray[i] )
result++
}
// in this comparsion if the digits are equale in value and location result will be incremented