thanks.

void setup() {

  size(300, 300);
  background(255);
  array();
}

void array() {

  int[][] arrayinit = {
    { 10, 5, 3, 55, 90 }, 
    {  9, 4, 2, 32, 22 }, 
    {  3, 8, 5, 79, 22 }, 
    {  3, 8, 45, 4, 2 }, 
    {  3, 22, 5, 44, 4 }
  };

  int rows = 5;
  int cols = 5;

  int[] sum = new int[cols];
  int[] sum2 = new int[rows];
  stroke(0);
  for (int c=0; c<cols; c++) { // for every column
    for (int r=0; r<rows; r++) { // for every row
      rect(40*r, 30*c, 40, 30);
      text(arrayinit[c][r], 40*r, 30*c); //dont know if this is right
      sum[c] += arrayinit[r][c]; // sum up the values per column
      sum2[r] += arrayinit[r][c];
    }
  }

  println(sum[0]); 
  println(sum[1]); 
  println(sum[2]); 
  println(sum2[2]);
  println(arrayinit[2][2]);
}