Basic Bubble Sort with ArrayList in Java

In Bubble sort you need to compare only the adjacent elements and swap them(depending up on the condition).

If you are doing ascending order than comparing the adjacent elements and swap if(arr[j]>arr[j+1]). This moves the largest elements to the end in the first iteration.Thus there are n-1 iterations in outer loop to sort the array where n is the length of the array.

Read this first Bubble sort as the tutorial you mentioned is completely wrong

Corrected code

for (int i = 0; i < numbers.length-1; i++)
{
   for(int j = 0; j < numbers.length-i-1; j++)
   {
            if(numbers[j] > numbers[j + 1])
            {
                   tempVar = numbers [j + 1];
                   numbers [j + 1]= numbers [j];
                   numbers [j] = tempVar;
            }
   }
}

Here is the working link