Copy a 1*9 array into a 3*3 array – Java

I’m trying to copy a 1 by 9 array into a 3 by 3 array. I’m not sure why my output is just the number 1 moving across the array. Any help would be greatly appreciated.

public class arrayTest{
   public static void main(String [] args)
   {
      int A []  = {1,2,3,4,5,6,7,8,9};
      int B [][] = new int [3][3]; 
   
      int i = 0, k, j;
   
      for(k = 0; k < 3; k++)  
         for(j = 0; j < 3; j++ ){
            B[k][j] = A[i];
            k++;
         }
         
      for(k = 0; k < 3; k++)
      {
         for(j = 0; j< 3; j++)
            System.out.print(B[k][j] + " ");
         System.out.println(); 
      }
   }
}

>Solution :

You need to convert the 2D coordinates from the loop counters into an index into the 1D array:

int A []  = {1,2,3,4,5,6,7,8,9};
int B [][] = new int [3][3]; 

for (int k=0; k < 3; k++) {
    for (int j=0; j < 3; j++) {
        B[k][j] = A[k*3 + j];
     }
}

System.out.println(Arrays.deepToString(B));
// [[1, 2, 3], [4, 5, 6], [7, 8, 9]]