Sample Code 23-3

// A program to illustrate 2D array parameter passing

public void printTable ( int[][] pTable )
{
  for ( int row = 0; row < pTable.length; row++ )
  {
    for ( int col = 0; col < pTable[row].length; col++ )
    {
      System.out.printf( “%4d”, pTable[row][col] );
    }
    System.out.println();
  }
}

The printTable method uses a reference parameter, int[][] pTable. The local identifier pTable serves as an alias for the actual parameter grid passed to the method.

When a program is running and it tries to access an element of an array, the Java virtual machine checks that the array element actually exists. This is called bounds checking. If the program tries to access an array element that does not exist, the Java virtual machine will generate an ArrayIndexOutOfBoundsException exception. Ordinarily, this will halt the program.