Swap the first and the last columns of array.

Question

I`ve done it correctly for square matrixes and those when columns > strings. But something`s wrong with cases when strings > columns. How to fix it?

import java.util.Scanner;

public class Lab5_2 {

static void lolSwap(String[][] matrix, byte n, byte m) {
// Auxiliary array
String[] helpingHand = new String[n];
if (n >= m) {
for (byte i = 0; i < m; i++) {
helpingHand[i] = matrix[n - 1][i];
}
for (byte i = 0; i < m; i++) {
matrix[n - 1][i] = matrix[0][i];
matrix[0][i] = helpingHand[i];
}
} else {
for (byte i = 0; i < n; i++) {
helpingHand[i] = matrix[n - 1][i];
}
for (byte i = 0; i < n; i++) {
matrix[n - 1][i] = matrix[0][i];
matrix[0][i] = helpingHand[i];
}
}
}

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
byte n = input.nextByte();
byte m = input.nextByte();
input.close();
if (n < 2) {
throw new IllegalArgumentException("There must be at least 2 columns");
}

String[][] array = new String[n][m];
for (byte i = 0; i < n; i++) {
for (byte j = 0; j < m; j++) {
array[i][j] = "a" + (i + 1) + (j + 1);
System.out.print(array[i][j] + "\t");
}
System.out.println();
}
System.out.println("\n");
lolSwap(array, n, m);
for (byte i = 0; i < n; i++) {
for (byte j = 0; j < m; j++) {
System.out.print(array[i][j] + "\t");
}
System.out.println();
}
}
}

Answer 1

if "n" is the number of columns and "m" is number of rows then shouldn't it be ,

String[][] array = String[M][N] ;

?

Answer 2

Yes, it is.