Transpose matrix in Java

public int[][] transpose(int[][] m) {
 int[][] ans = new int[m[0].length][m.length];
 for (int rows = 0; rows < m.length; rows++) {
 for (int cols = 0; cols < m[0].length; cols++) {
 ans[cols][rows] = m[rows][cols];
 }
 }

 return ans;
}