How to convert custom class list to two dimensional array-CodePudding

I have class Box, which describes parameters of box (height, width, length):

public class Box {
public int h; 
public int w; 
public int l; 

public Box(int h, int w, int l) {
    this.h = h;
    this.w = w;
    this.l = l;
}

In input i have list of boxes, how to convert it to two dimensional array? One row = one box:

 List<Box> listBox1 = new ArrayList<>();
 listBox1.add(new Box(12, 11, 12));
 listBox1.add(new Box(11, 12, 12));
 listBox1.add(new Box(1, 1, 1));
 listBox1.add(new Box(67, 34, 13));

Output:

12 11 12 // 1st box and e.t.c...
11 12 12
1  1  1
67 34 13

CodePudding user response：

Your two dimensional array should of size (m * n) where m is length of box list and n is fixed 3 for three properties (h, w, l).

Get the length of arrayList int length = listBox1.size();

A sample code as below.

      int[][] array = new int[length][3];
      for(Box box : listBox1){
            int index = listBox1.indexOf(box);
            array[index][0] = box.h;
            array[index][1] = box.w;
            array[index][2] = box.l;
        }

      for(int i=0 ; i<array.length; i  ){
         System.out.println(array[i][0]   " "   array[i][1]   " "   array[i][2]);
       }