Why is this bubble sort code not working?

Question

private static int[] array = { 121, 19, 49, 11, 7, 13, 25 };
public int[] bubbleSort(int[] a) {
for (int i = 0; i < a.length; i++) {
for (int j = i + 1; j < a.length; j++) {
if (a[i] > a[j]) {
int num = a[i];
a[i] = a[j];
a[j] = num;
}
}
}
return a;
}

Answer 1

public class Program
{
private static int[] array = { 121, 19, 49, 11, 7, 13, 25 };

public static void main(String[] args) {
int[] arr;
arr=bubbleSort(array);
for(int i=0;i<arr.length;i++)
System.out.println(arr[i]);
}

public static int[] bubbleSort(int[] a) {
for (int i = 0; i < a.length; i++) {
for (int j = i + 1; j < a.length; j++) {
if (a[i] > a[j]) {
int num = a[i];
a[i] = a[j];
a[j] = num;
}
}
}
return a;
}
}

Answer 2

Class A
{
Scanner sc=new Scanner(System.in);
System.out.println("Enter the Numbers ");
int temp=0;
int n=sc.NextInt();
int a[]=new int[n];
System.out.println("Enter elements to be short");
for(int i=0;i<n;i++)
{
a[i]=sc.NextInt();
}
System.out.println("Elements without Sorting");
for(int i=0;i<n;i++)
{
System.out.println(a[i]);}
for(Int i=0;i<n;i++){
for(int j=0;j<n;j++){
if(a[i]<b[j])
{ temp =b[j];
b[j]=a[i];
a[i]=temp;}
System.out.println(“After shorting ");
for(int i=0;i<n;i++)
{
System.out.println(a[i];
}
}
}

Answer 3

Here are some things you might want to try:

- Instead of running this entirely in for loops, try starting with a while loop, with the exit condition being whether or not the loop is sorted. Then run a single for loop inside of that.

- Your second for loop is going to run out of bounds. Since j is always initially set to i + 1, when i reaches the last index of your array, j is going to be 1 past the array's length. So make sure i is always less than a.length - 1.

- Methods can't be nested inside other methods. Try moving bubbleSort(int[] a) outside of the main method, then from the main method, call bubbleSort.

- Instead of trying to reassign the values in a, try creating a new array and copying everything from a into that. To do that, write: int[] sorted = a; before you do any sorting operations. Then do all the sorting on the "sorted" array.

Hope this helps :)

Answer 4

import java.util.Scanner;

public class Program2 {

public static void main(String[] args) {
// TODO Auto-generated method stub
int n;
Scanner scan = new Scanner(System.in);
System.out.println("enter the number");
n=scan.nextInt();
int a[]=new int[n];
System.out.println("enter "+n+" elements to sort");
for(int i=0;i<n;i++){
a[i]=scan.nextInt();
}
System.out.println("elements before sorting.....................");
for(int i=0;i<n;i++){
System.out.println(a[i]+" ");
}
int temp;
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
if(a[i]<a[j]){
temp=a[i];
a[i]=a[j];
a[j]=temp;
}
}
}
System.out.println("elements after sorting..................");
for(int i=0;i<n;i++){
System.out.println(a[i]+" ");
}
}

}