递归永远不会结束，即使返回语句

Question

我可能不明白return语句的作用（我认为它只是返回一个变量并允许我退出循环）。我试图更好地理解递归，但这似乎永远不会退出。

import java.util.Arrays; 
import java.util.List; 

public class main { 

    public static void main(String[] args) { 
     System.out.println("Starting.."); 
     List<Integer> list_to_start = Arrays.asList(new Integer[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}); 
     String[] name_of_list_to_start = new String[] {"grapes", "Strawberries", "Raspberries", "Blackberries", "Pineapples", "Oranges", "Prunes", "Pears", "cherries", "Peaches", "Apples"};  
     System.out.println(list_to_start.size()); 
     counter(list_to_start.size(), list_to_start, name_of_list_to_start); 
    } 

    private static void counter(int length, List<Integer> list_to_start, String[] name_of_list_to_start) { 
     // TODO Auto-generated method stub 
     if (length == 0) { 
      System.out.println("List is empty now"); 
      for (int i = 0; i>=list_to_start.size(); i++) { 
       System.out.println(name_of_list_to_start[i] + " = " + list_to_start.get(i)); 
      } 
      return; 
     } 
     Integer x_lenght = (Integer) list_to_start.get(length-1); 
     for (int i = 0; i<=5; i++) { 
      //System.out.println(i); 
      if (length != 0) { 
       list_to_start.set((length-1), i); 
       counter((length-1), list_to_start, name_of_list_to_start); 
       list_to_start.set((length-1), 0); 
      } 
     } 
    } 
} 

基本上我试图做的是，用递归，找出0-5所有组合的10种不同的水果（这只是我学习，不homework..not学生）。

任何想法我做错了什么？为什么这个程序不能用return语句停止？

更新：如果没有人有同样的问题，这里是上述代码的工作版本（保持断码这样的答案有意义）：

import java.util.Arrays; 
import java.util.List; 

public class main { 

    public static void main(String[] args) { 
     System.out.println("Starting.."); 
     List<Integer> list_to_start = Arrays.asList(new Integer[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}); 
     String[] name_of_list_to_start = new String[] {"grapes", "Strawberries", "Raspberries", "Blackberries", "Pineapples", "Oranges", "Prunes", "Pears", "cherries", "Peaches", "Apples"};  
     System.out.println(list_to_start.size()); 
     counter(list_to_start.size(), list_to_start, name_of_list_to_start); 
    } 

    private static void counter(int length, List<Integer> list_to_start, String[] name_of_list_to_start) { 
     // TODO Auto-generated method stub 
     if (length == 0) { 
      //System.out.println("List is empty now"); 
      for (int i = 0; i<list_to_start.size(); i++) { 
       //(name_of_list_to_start[i] + " = " + list_to_start.get(i)); 
       int k = i +2; 
       int y = k -1; 
      } 
      //System.out.println("********"); 
      return; 
     } 
     Integer x_lenght = (Integer) list_to_start.get(length-1); 
     for (int i = 0; i<=5; i++) { 
      //System.out.println(i); 
      if (length != 0) { 
       list_to_start.set((length-1), i); 
       counter((length-1), list_to_start, name_of_list_to_start); 
       list_to_start.set((length-1), 0); 
      } 
     } 
    } 
} 

Answer 1

你确定这是一个无限循环，而不只是一个很长的序列？

在每个级别循环5次，每次分支到另一个递归。你有10个级别，所以你最多可以在底层调用5^10个函数，或者调用9,765,625个System.out.println！

您的返回语句不在循环中。 return语句退出当前的函数调用......但您在这里有超过1000万次函数调用，所以它必须返回很多次。

Answer 2

你的病情for循环时长= 0应该是

i<list_to_start.size() 

和莱利说，你的递归需要有所微调。