hey im stuck on some java code im trying to write 2 seperate methods to swap eac

Question

hey im stuck on some java code im trying to write 2 seperate methods to swap each value in each row and column with its opposite for examples if i had a 2d array   arr1 = {{1,2,3,4,5},{6,7,8,9,0}}: for the row swap method it would swap 1-6 and 2-5 and 3-4 and so on for the next row....... I have written this code and it does compile properly:

static void swapArrays(int [][] grades){
           for (int i =0; i<grades.length; i++){
               int y = grades[i].length;
               for(int j=0;j<y/2; j++){
                   int temp = grades[i][j];
                   grades[i][j] =grades[i][y-j-1];
                   grades[i][y-j-1]= temp;
               }
               for (int x=0; x<grades.length-1; x++)
                   System.out.print(grades[i][x] + " ");
               System.out.println();
           }
       }

my problem is i need to the same thing except it needs to swap the values in the columns for the other method the same way as that method swaps the rows... and i cant seem to get it... help please!!

Explanation / Answer

Hey here is your answer:

I have also corrected your row swapping code, it was not printing whole array.

public class Swaparr {

static void main() {
int arr[][] = {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 0}};
swapArrays(arr);
System.out.println();
swapColumns(arr);
}

static void swapArrays(int[][] grades) {
for (int i = 0; i < grades.length; i++) {
int y = grades[i].length;
for (int j = 0; j < y / 2; j++) {
int temp = grades[i][j];
grades[i][j] = grades[i][y - j - 1];
grades[i][y - j - 1] = temp;
}
for (int x = 0; x < grades[i].length; x++) {
System.out.print(grades[i][x] + " ");
}
System.out.println();
}
}

static void swapColumns(int[][] grades) {
int cols = grades[0].length;
int y = grades.length;
for (int i = 0; i < cols; i++) {
for (int j = 0; j < y / 2; j++) {
int temp = grades[j][i];
grades[j][i] = grades[y - j - 1][i];
grades[y - j - 1][i] = temp;
}
}
for (int i = 0; i < grades.length; i++) {
for (int x = 0; x < grades[i].length; x++) {
System.out.print(grades[i][x] + " ");
}
System.out.println();
}
}
}

OUTPUT:

run:
5 4 3 2 1
0 9 8 7 6

0 9 8 7 6
5 4 3 2 1

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