java/03-count/Count.java


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/*
 * Run this as below:
 *    java Count
 *    java Count 1
 *    java Count 3 8
 *    java Count 5 1
 *    java Count 2 Kamal
 *    java Count 5 12.3
 *    java Count 3 10000000000000000000000000000000000000000000000000
 */
public class Count {
  public static void main(String[] args) {
    if (args.length < 2) {
      System.err.println("[ERROR] Type two integers as arguments.");
      System.exit(1);
    }

    int start = 0;
    int end = 0;

    try {
      start = Integer.parseInt(args[0]);
      end = Integer.parseInt(args[1]);
    } catch (NumberFormatException nfe) {
      System.err.println("[ERROR] You didn't provide integer arguments.");
      // System.err.println("Details: " + nfe.getMessage());
      System.exit(2);
    }

    if (start > end) {
      System.err.println("[ERROR] Start is greater than end.");
      System.exit(3);
    }

    for (int i = start; i <= end; i++) {
      System.out.println(i);
    }
  }
}