I am trying to make a rounding function

Projects Programming
4

You should use && instead of the comma.
The program should look like this

int roundrl(int rl) {
  if (rl < 100 && rl > -1) {
    rl = 0;
  } else if (rl < 200 && rl > 99) {
    rl = 100;
  } else if (rl < 300 && rl > 199) {
    rl = 200;
  }
  else if (rl < 400 && rl > 299) {
    rl = 300;
  } else if (rl < 500 && rl > 399) {
    rl = 400;
  } else if (rl < 600 && rl > 499) {
    rl = 500;
  } else if (rl < 700 && rl > 599) {
    rl = 600;
  } else if (rl < 800 && rl > 699) {
    rl = 700;
  } else if (rl < 900 && rl > 799) {
    rl = 800;
  } else if (rl < 1000 && rl > 899) {
    rl = 900;
  } else if (rl < 1100 && rl > 999) {
    rl = 1000;
  }
  return rl;
}