Java How to Program Fourth Edition - DCC

Chapter 7 Arrays 345
25
26 outputArea.append( "\nValues in array2 by row are\n" );
27 buildOutput( array2 );
28 }
29
30 // append rows and columns of an array to outputArea
31 public void buildOutput( int array[][] )
32 {
33 // loop through array's rows
34 for ( int row = 0; row < array.length; row++ ) {
35
36 // loop through columns of current row
37 for ( int column = 0;
38 column < array[ row ].length;
39 column++ )
40 outputArea.append( array[ row ][ column ] + " " );
41
42 outputArea.append( "\n" );
43 }
44 }
45 }
Fig. Fig. 7.15 7.15 Initializing multidimensional arrays (part 2 of 2).
The program declares two arrays in method init. The declaration of array1 (line
20) provides six initializers in two sublists. The first sublist initializes the first row of the
array to the values 1, 2 and 3. The second sublist initializes the second row of the array to
the values 4, 5 and 6. The declaration of array2 (line 21) provides six initializers in three
sublists. The sublist for the first row explicitly initializes the first row to have two elements
with values 1 and 2, respectively. The sublist for the second row initializes the second row
to have one element with value 3. The sublist for the third row initializes the third row to
the values 4, 5 and 6.
Line 24 of method init calls method buildOutput (defined at lines 31–44) to
append each array’s elements to outputArea (a JTextArea). Method buildOutput
specifies the array parameter as int array[][] to indicate that the method receives a
double-subscripted array as an argument. Note the use of a nested for structure (lines 34–
43) to output the rows of a double-subscripted array. In the outer for structure, the expression
array.length determines the number of rows in the array. In the inner for structure,
the expression array[ row ].length determines the number of columns in the
current row of the array. This condition enables the loop to determine the exact number of
columns in each row.
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