Thread: Syntax for 3D array enhanced

I learned 2D arrays si I though I would just take a stab at 3D but I cannot figure out the correct syntax. Here is what I have:

public class ThreeDArray
{
	public static void main(String[] args)
	{
		int[][][] x = new int[2][3][4];
		x[0][0][0] = 5;
		x[0][1][0] = 3;
		x[0][2][0] = 1;
		x[1][0][0] = 5;
		x[1][1][0] = 3;
		x[1][2][0] = 1;
 
 
 
		for(int[] i: x )
		{
			for(int j : i)
			{
				for(int m : j)
				{
					System.out.print(m + " ");
				}
			}
			System.out.println();
 
		}
 
	}
}

here's the two errors I am getting:

ThreeDArray.java:15: error: incompatible types
		for(int[] i: x )
		             ^
  required: int[]
  found:    int[][]
ThreeDArray.java:19: error: for-each not applicable to expression type
				for(int m : j)
				            ^
  required: array or java.lang.Iterable
  found:    int
2 errors

thanks in advance!

The error message says it all. i should be a reference to a reference i.e with [][] instead of [], and j should have one []

for(int [][] i : x)
...
for(int[] j : i)

But I would recommend plain old for loop with a counter for arrays with fixed size such as yours.

what do you mean by "plain old loop?"

thanks

Originally Posted by mwr76

what do you mean by "plain old loop?"

thanks

I mean something like

for(int i = 0;i < 2;i++)
  for(int j = 0;j < 3;j++)
      for(int k = 0;k < 4;k++)
          System.out.println(x[i][j][k])

Personally I find this simpler than the first method and is what is commonly thought as a method of accessing
fixed size arrays. More here Multi-dimensional arrays in Java

You can print out contents of nested arrays with java.util.Arrays.deepToString(...), or you can roll your own array-descent code using the for..each style (ideal for this), or you can use loop indexes *but remember to loop from 0 to < array.length* - don't hard-code your array index maxes. For example:

for (int i = 0; i < arrayIndex.length; i++)
  for (int j = 0; j < arrayIndex[i].length; j++)
  { /* do something */ }