徐珮芸Java遞迴函數Recursion funtion,遞迴Recursion

w3schools學習Java遞迴函數recursion

public class Main {//徐珮芸w3schools遞迴函數recursion
  public static void main(String[] args) {
    int x = 10;
    for (int i=0;i < x; i++){        //使用for迴圈
    System.out.print(i +"累加等於 "  + sum (i));
    System.out.println("累乘等於 " + f(i));}
  }
  public static int sum(int k) { //定義sum函數,參數k
    if (k > 0) {
      return k + sum(k - 1);      //sum函數呼叫sum,f(f(k))
    } else {
      return 0;}
  }
  public static int f(int k) { //定義f函數,參數f
    if (k > 0) {
      return k * f(k - 1);      //f函數呼叫f,f(f(k))
    } else {
      return 1;
     } //0!=1, 5!=5*4*3*2*1
  }
}