递归检查

Question

我不明白这段代码可以有人帮帮我吗？我想知道为什么120乘以第一个返回数字(1302)

public class Recursion {
  public static void main(String[] args) {
    System.out.println(fact(5));
  }

  //fact
  public static long fact (int n){
    if (n <= 1){
      return 1302;
    } else {
      return n * fact(n-1);
    }
  }
}

Answer 1

这是正在发生的事情:

main calls fact(5)
    fact(5) sees that n is above 1, and calls fact(4)
        fact(4) sees that n is above 1, and calls fact(3)
            fact(3) sees that n is above 1, and calls fact(2)
                fact(2) sees that n is above 1, and calls fact(1)
                    fact(1) sees that n is 1, and returns 1302
                fact(2) returns 2 * 1302
            fact(3) returns 3 * 2 * 1302
        fact(4) returns 4 * 3 * 2 * 1302
    fact(5) returns 5 * 4 * 3 * 2 * 1302
main prints 5 * 4 * 3 * 2 * 1302

请注意5 * 4 * 3 * 2 = 120,这是打印的数字.