Unit #8 Test Review

interchange of rows into columns and columns into rows

• diagonal elements

• boundary elements

• transpose of a matrix

• 2D array

elements that are not surrounded by other elements in all four directions

• diagonal elements

• boundary elements

• transpose of a matrix

• 2D array

elements that either have the same row index and column index, or have a sum of the row index and column index that is equal to the array size – 1

• diagonal elements

• boundary elements

• transpose of a matrix

• 2D array

visualized as a grid (or table) with rows and columns with the same type of data

• diagonal elements

• boundary elements

• transpose of a matrix

• 2D array

public static void stationery(){

String[][] item = new String[][] { {"eraser","pen"},{"pencil","ruler"}, {"charts","sheets"},{"notebook","maps"}, {"clock","flash cards"},{"diary","colored pencil"} };

int m = item.length; // number of rows   

int n = item[0].length; // number of columns  

for(int col = 0 ; col < n; col++){

System.out.print(item[0][col] + " ");

System.out.print(item[m-1][col] + " "); }

}

}

What will be the output of the above code segment?

• pen colored pencil eraser diary

• clock flash cards diary colored pencil eraser pen pencil ruler charts sheets notebook maps

• eraser diary pen colored pencil

• eraser pen pencil ruler charts sheets notebook maps clock flash cards diary colored pencil

• eraser ruler clock colored pencil

Consider a method defined with a String 2D array parameter.

boolean test(String[][] val)

Which of the following is the correct method call statement?

• boolean b = test(String); // String is a String 2D array with values

• boolean b = test(String[][]); // String is a String 2D array with values

• boolean b = test(string[][]); // string is a String 2D array with values

• boolean b = test(string); // string is a String 2D array with values

• string = test(boolean); // string is a String 2D array with values

int n= arr.length;

System.out.println("left top corner: " + arr[0][0]);

System.out.println("right top corner: " + arr[0][n - 1]);

System.out.println("left bottom corner: " + arr[n - 1][0]);

System.out.println("right bottom corner: " + arr[n - 1][n - 1]);

What will be the output if the above statements are executed with a square matrix, arr?

• It will print nonboundary elements.

• It will print major diagonal (left to right) elements.

• It will print minor diagonal (right to left) elements.

• It will print boundary elements.

• It will print corner elements.

Which of the following is/are true for Java methods?

I. Methods can have only one 2D array as a parameter.

II. Methods can return multiple 2D arrays.

III. Methods can have a 2D array as a parameter along with other types.

• I only

• II only

• III only

• I and II

• I and III

void find(int[] arr){ 

k=row-1;

i=0;

for(j=0;j< arr.length;j++) {

temp=arr[i][j]; arr[i][j]=arr[k][j]; arr[k][j]=temp; }

}

Which of the following is true with respect to the above code?

• The code interchanges row 0 and row 1.

• The code interchanges column 0 and column 1.

• The code copies the value of row 0 to row 1.

• The code interchanges the first column and the last column.

• The code interchanges the first row and the last row.