The Essence of OOP using Java, Array Objects, Part 2, Page 8

/*File Array07.java
Copyright 2002, R.G.Baldwin

This program illustrates three 
different ways to emulate a traditional
rectangular array in Java.  Two of 
those ways are essentially ragged
arrays with equal-length sub arrays.

The program also illustrates two ways
to create ragged arrays in Java.

Tested using JDK 1.3 under Win 2000.
**************************************/

public class Array07{
  public static void main(
                        String[] args){

    //Create an array structure that
    // emulates a traditional 
    // rectangular array with two rows
    // and three columns.  This
    // approach requires all rows to
    // be the same length.
    Object[][] v1 = new Object[2][3];
    //Populate the array elements with
    // references to objects of type 
    // Integer.
    for(int i=0;i<v1.length;i++){
      for(int j=0;j<v1[i].length;j++){
        v1[i][j] = 
              new Integer((i+1)*(j+1));
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v1.length;i++){
      for(int j=0;j<v1[i].length;j++){
        System.out.print(
                       v1[i][j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
    System.out.println();//new line   

    //Create a ragged array with two
    // rows.  The first row has three
    // columns and the second row has
    // three columns.  The length of
    // each row could be anything, but
    // was set to three to match the
    // above array structure.
    Object[][] v2 = new Object[2][];
    v2[0] = new Object[3];
    v2[1] = new Object[3];
    //Populate the array elements with
    // references to objects of type 
    // Integer.
    for(int i=0;i<v2.length;i++){
      for(int j=0;j<v2[i].length;j++){
        v2[i][j] = 
              new Integer((i+1)*(j+1));
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v2.length;i++){
      for(int j=0;j<v2[i].length;j++){
        System.out.print(
                       v2[i][j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
    System.out.println();//new line

    //Create a one-dimensional array
    // of type Object, which contains
    // references to array objects of 
    // type Object.  The secondary
    // array objects could be of any
    // length, but were set to three
    // to match the above array 
    // structure.
    Object[] v3 = new Object[2];
    v3[0] = new Object[3];
    v3[1] = new Object[3];
    //Populate the array elements with
    // references to objects of type 
    // Integer.
    for(int i=0;i<v3.length;i++){
      for(int j=0;
            j<((Object[])v3[i]).length;
                                  j++){
        ((Object[])v3[i])[j] = 
              new Integer((i+1)*(j+1));
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v3.length;i++){
      for(int j=0;
            j<((Object[])v3[i]).length;
                                  j++){
        System.out.print(
           ((Object[])v3[i])[j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
    System.out.println();//new line

    //Create a ragged array with two
    // rows.  The first row has two
    // columns and the second row has
    // three columns.
    Object[][] v4 = new Object[2][];
    v4[0] = new Object[2];
    v4[1] = new Object[3];
    //Populate the array elements with
    // references to objects of type 
    // Integer.
    for(int i=0;i<v4.length;i++){
      for(int j=0;j<v4[i].length;j++){
        v4[i][j] = 
              new Integer((i+1)*(j+1));
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v4.length;i++){
      for(int j=0;j<v4[i].length;j++){
        System.out.print(
                       v4[i][j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
    System.out.println();//new line

    //Create a one-dimensional array
    // of type Object, which contains
    // references to array objects of 
    // type Object.  The secondary
    // array objects could be of any
    // length, but were set to two and
    // three to match the ragged array 
    // above.
    Object[] v5 = new Object[2];
    v5[0] = new Object[2];
    v5[1] = new Object[3];
    //Populate the array elements with
    // references to objects of type 
    // Integer.
    for(int i=0;i<v5.length;i++){
      for(int j=0;
            j<((Object[])v5[i]).length;
                                  j++){
        ((Object[])v5[i])[j] = 
              new Integer((i+1)*(j+1));
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v5.length;i++){
      for(int j=0;
            j<((Object[])v5[i]).length;
                                  j++){
        System.out.print(
           ((Object[])v5[i])[j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
    System.out.println();
   
    //Create a one-dimensional array
    // of type int, which contains
    // references to array objects of 
    // type Object.  The secondary
    // array objects could be of any
    // length.
    Object[] v6 = new Object[2];
    v6[0] = new int[7];
    v6[1] = new int[3];
    //Now illustrate that the elements
    // of the leaves of a ragged array
    // implemented in this manner can
    // contain primitive values.
    // Populate the array elements with
    // type int.
    for(int i=0;i<v6.length;i++){
      for(int j=0;
            j<((int[])v6[i]).length;
                                  j++){
        ((int[])v6[i])[j] = (i+2)*(j+2);
      }//end inner loop
    }//end outer loop
    //Display the array elements
    for(int i=0;i<v6.length;i++){
      for(int j=0;
            j<((int[])v6[i]).length;
                                  j++){
        System.out.print(
           ((int[])v6[i])[j] + " ");
      }//end inner loop
      System.out.println();//new line
    }//end outer loop
   
  }//end main
}//end class Array07
//===================================//

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