I am using Java Arrays.sort in order to sort elements of a two dimensional array:
int[][] RAM = new int[4][10000];
I fill the RAM array with integers and then call:
for (i=0;i<4;i++){
Arrays.sort(RAM[i]);
System.out.println(i);
}
This results in all elements of RAM[][] being filled with zeros. What am I doing wrong?
Did you actually fill the Array with numbers first? And if you did, you are only printing out the First part of your 2D array. You need to print out all 40,000 entries. 10,000 for each array in array. So [0][0...9999], [1][0...9999] etc.
public static void show (int [][] list)
{
System.out.println ("- show: -");
for (int [] ia : list) {
for (int i : ia)
System.out.print (i + ", ");
System.out.println ();
}
System.out.println ("---");
}
static Random random = new Random ();
public static void main (String [] args)
{
int[][] RAM = new int[4][2];
for (int i = 0; i < 4; ++i)
{
for (int j = 0; j < 2; ++j)
{
RAM[i][j] = random.nextInt (20);
System.out.print (i*2 +j);
}
}
show (RAM);
for (int i=0; i<4; i++) {
Arrays.sort (RAM[i]);
}
show (RAM);
System.out.println ();
}
Result:
- show: -
8, 13,
12, 10,
16, 3,
7, 1,
---
- show: -
8, 13,
10, 12,
3, 16,
1, 7,
---
int[4][10000] whereas yours is int[4][2]. The sort method is putting his sorted values at the very end; resulting in the loop printing only zeros - we assume the sort method will keep the excess zeros as they are(which obviously doesn't happen). So we need to pass the indexes as well - Arrays.sort(RAM[i], 0, 2). I can't tell what you had in mind either - but I'd guess you showed him what worked, and maybe he just used your code. That's just a guess, though.I think the reason is that you didn't set a value for all elements of your array. For the item you didn't initialize, the default value is 0. Thus when you sort the all items in the array, the 0s are swapped to the first part of your array. If you output the first parts of the array, all you see are zeros. I guess so.
