Use the while loop to calculate sum in Java

public class Main {
  public static void main(String[] args) {
    int limit = 20;
    int sum = 0;/*from   w  ww.j a va  2 s  . c o  m*/
    int i = 1;

    while (i <= limit) {
      sum += i++;
    }
    System.out.println("sum = " + sum);
  }
}