Java Program to calculate trace of a given matrix

This is a Java Program which calculates the trace of a matrix.

Generally trace of a square matrix is calculated as the sum of all the diagonal elements in a matrix.

PROGRAM : 

package codingcorner.in;

import java.util.Scanner;

public class Trace {
 public static void main(String[] args) {
  int rows, columns, i, j, trace = 0;
  Scanner scan = new Scanner(System.in);
  System.out.print("Enter order of matrix :  \t");
  rows = scan.nextInt();
  columns = scan.nextInt();
  int matrix[][] = new int[rows][columns];
  System.out.print("Enter elements of the matrix :\n");
  for (i = 0; i < rows; i++) {
   for (j = 0; j < columns; j++) {
    System.out.print("Enter element m" + (i + 1) + (j + 1) + ":\t");
    matrix[i][j] = scan.nextInt();
   }
  }
  scan.close();
  System.out.print("\n\nMATRIX is :\n");
  for (i = 0; i < rows; i++) {
   for (j = 0; j < columns; j++)
    System.out.print(matrix[i][j] + "\t");

   System.out.print("\n");
  }
  System.out.print("\nIts TRACE is :\t");
  for (i = 0; i < rows; i++) {
   for (j = 0; j < columns; j++) {
    if (i == j)
     trace = trace + matrix[i][j];

   }
  }
  System.out.print(trace);
 }
}

OUTPUT :

Java - Trace of a matrix