Recursion: a method (function) calls itself : Recursive Method « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Recursive Method

Characteristics of Recursive Methods:

1. Method calls itself.
2. When it calls itself, it solves a smaller problem.
3. There is a smallest problem that the routine can solve it, and return, without calling itself.

public class MainClass {
  public static void main(String[] args) {
    int theAnswer = triangle(12);
    System.out.println("Triangle=" + theAnswer);
  }

  public static int triangle(int n) {
    if (n == 1)
      return 1;
    else
      return (n + triangle(n - 1));
  }
}

Triangle=78