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Chapter 8 Check Point Questions

Section 8.2
▼8.2.1
Declare an array reference variable for a two-dimensional array of int values, create a 4 × 5 int matrix, and assign it to the variable.
▼8.2.2
Can the rows in a two-dimensional array have different lengths?
▼8.2.3
What is the output of the following code? 
int[][] array = new int[5][6];
int[] x = {1, 2};
array[0] = x;
System.out.println("array[0][1] is " + array[0][1]);
▼8.2.4
Which of the following statements are valid? 
int[][] r = new int[2]; 	
int[] x = new int[];
int[][] y = new int[3][];
int[][] z = {{1, 2}};
int[][] m = {{1, 2}, {2, 3}};
int[][] n = {{1, 2}, {2, 3}, };
Section 8.3
▼8.3.1
Show the output of the following code: 
int[][] array = {{1, 2}, {3, 4}, {5, 6}};
for (int i = array.length - 1; i >= 0; i--) {
  for (int j = array[i].length - 1; j >= 0; j--)
    System.out.print(array[i][j] + " ");
  System.out.println();
}
▼8.3.2
Show the output of the following code: 
int[][] array = {{1, 2}, {3, 4}, {5, 6}};
int sum = 0;
for (int i = 0; i < array.length; i++) 
  sum += array[i][0];
System.out.println(sum);
Section 8.4
▼8.4.1
Show the output of the following code: 
public class Test {
  public static void main(String[] args) {
    int[][] array = {{1, 2, 3, 4}, {5, 6, 7, 8}};
    System.out.println(m1(array)[0]);
    System.out.println(m1(array)[1]);
  }

  public static int[] m1(int[][] m) {
    int[] result = new int[2];
    result[0] = m.length;
    result[1] = m[0].length;
    return result;
  }
}
Section 8.5
▼8.5.1
8.5.1 How do you modify the code so that it also displays the highest count and the student with the highest count?
Section 8.6
▼8.6.1
What happens if the input has only one point?
Section 8.7
▼8.7.1
What happens if the code in line 51 in Listing 8.4 is changed to 
if (row != i && col != j && grid[row][col] == grid[i][j])
Section 8.8
▼8.8.1
Declare an array variable for a three-dimensional array, create a 4 × 6 × 5 int array, and assign its reference to the variable.
▼8.8.2
Assume char[][][] x = new char[12][5][2], how many elements are in the array? What are x.length, x[2].length, and x[0][0].length?
▼8.8.3
Show the output of the following code: 
int[][][] array = {{{1, 2}, {3, 4}}, {{5, 6},{7, 8}}};
System.out.println(array[0][0][0]);
System.out.println(array[1][1][1]);