This document provides instructions for a programming exercise to write a Java program that sorts the columns of a 2D array. The program must include a method called sortColumns() that returns a new sorted array without modifying the original. The main method should prompt the user to input a 3x3 matrix, display the original and sorted arrays, and allow the user to rerun the program with different inputs using a loop. The code must be properly formatted, documented and output must be organized with escape characters.

1. Design and implement a Java program for programming exercise 8.27, page 315 (name it
Columnsorting) as described in the problem statement. Write method sortColumns() as specified
(you may change the element type to integer). Notice that this method returns a new array, the
original array remains unchanged. To test this method, the main method of your program
prompts the user to enter a two-dimensional array and displays the original array followed by the
column-sorted array as shown in the sample run. Design the main method of your program such
that it allows the user to re-run the program with different inputs (i.e., use a loop). Document
your code, and organize and space the outputs properly. Use escape characters and formatting
objects when applicable.
Solution
ColumnSorting.java
public class ColumnSorting {
public static void main(String[] args) {
java.util.Scanner in = new java.util.Scanner(System.in);
System.out.println("Enter a 3-by-3 matrix row by row: ");
String firstRow = in.nextLine();
String firstRowValues[] = firstRow.split("s+");
String secondRow = in.nextLine();
String secondRowValues[] = secondRow.split("s+");
String thirdRow = in.nextLine();
String thirdRowValues[] = thirdRow.split("s+");
double a[][] = new double[3][3];
for(int i=0; i m[j+1][i]){
temp = m[j][i];
m[j][i] = m[j+1][i];
m[j+1][i] = temp;
}
}
}
return m;
}
}
Output:

2. Enter a 3-by-3 matrix row by row:
0.15 0.875 0.375
0.55 0.005 0.225
0.30 0.12 0.4
The column-sorted array is
0.15 0.005 0.225
0.3 0.12 0.375
0.55 0.875 0.4