Multiply Operation for the Countdown Math Game on the SSaurel's Channel

Multiply.java

package com.ssaurel.countdowngame;

public class Multiply implements Operation {

  @Override
  public int eval(int x, int y) {
    int r = x * y;

    if (r <= x || r <= y) {
      return 0;
    } else {
      return r;
    }
  }

  @Override
  public String symbol() {
    return "*";
  }

}