函数在递归循环后未正确结束

Question

我正在尝试建立一个游戏风险的副本猫。我有一个while循环，它告诉你在攻击还没有结束的时候做一些事情。然后，我要求用户输入'end turn‘来结束turn，或者'continue’来再次递归调用攻击函数。问题是，在用户输入攻击几次之后，然后'end turn‘这个回合并没有结束，而是从头开始或重新开始。我非常感谢专家的眼睛来看我的代码，看看我遗漏了什么，提前谢谢。

public void attackOrSkip(Player player,Player[] playerArray, int playerId) {
        boolean attackFinished = false;
        int numUnitsAttackWith = 0;
        int defenceArmiesNumber =0;
        displayString(makeLongName(player) + ": Type 'attack' to attack or 'skip' to skip your turn...");
        String command = commandPanel.getCommand();
        displayString(PROMPT + command);
        if(command.equals("skip") ||command.equals("skip ") ||command.equals("s")) {
            return;
        }else if (command.equals("attack") ||command.equals("attack ")){
            displayString(PROMPT + command);
            //while the attack isn't finished
            while(attackFinished == false) {
                
                //get the country the user is attacking
                int countryAttackingFrom=countryFromCheck(playerId,player);
                //get the country to attack
                int countryToAttack = countryToCheck(player);
                //get the player who we are attacking
                int occupierPlayer =board.getOccupier(countryToAttack);
                
                
                if ((board.getNumUnits(countryAttackingFrom)) < 2) {
                    displayString("You dont have enough units on this country to make an attack!");
                    attackOrSkip(player, playerArray, playerId);
                    break;
                    }
                //if the country is adjacent to another one then you can attack else no
                else if(isAdjacent(countryAttackingFrom,countryToAttack)) {
                    
                    //check the number of unit to attack with
                    numUnitsAttackWith =numUnitsCheckerAttack(player,countryAttackingFrom);
                    //check the number of unit to defend with
                    defenceArmiesNumber = numUnitsCheckerDefence(player,countryToAttack);
                    
                    //roll the dice
                    player.rollDice(numUnitsAttackWith);
                    playerArray[occupierPlayer].rollDice(defenceArmiesNumber);
                    
                    //display the roll results
                    displayString(makeLongName(player) + "Rolled: "+printDie(player));
                    displayString(makeLongName(playerArray[occupierPlayer]) + "Rolled: "+printDie(playerArray[occupierPlayer]));
                    
                    }
                    displayString(makeLongName(player) + ": 'end turn' or 'continue'");
                    command = commandPanel.getCommand();
                    displayString(PROMPT + command);
                    if(command.equals("end turn")||command.equals("end turn ") ||command.equals("endturn")||command.equals("endturn ") ||command.equals("end")) {
                        attackFinished = true;
                        return;
                    }else if(command.equals("attack") ||command.equals("attack ")){
//                      break;
                    }else if(command.equals("continue") ||command.equals("continue ") ||command.equals("con")){
                        attackOrSkip(player,playerArray,playerId);
                    }else {
                        return;
                    }
                }else {
                    displayString(makeLongName(player) + ": ERROR, not adjacent countries");
                }
            }
        }
    }

Answer 1

好的-就像目前写的那样-每次你在方法中调用attackOrSkip -你最终在堆栈中低了一层-有了一组新的变量-

   attackFinished, numUnitsAttackWith, defenceArmiesNumber

当您离开递归(即通过返回)时，您最终得到了与进入递归调用之前一样的简单变量-请记住，Java是按值调用的(即使您可以传入对对象的引用，您也会获得一个值(调用时变量引用的当前值...并且将引用更改为指向不同的对象不会更改调用者引用)。

因此，无需查看您是否完成了正确的算法--我猜测，如果您使方法返回类型为布尔值并返回状态而不是什么都不返回，您就可以更新attackFinished，并且可能会发生正确的事情。

例如，更改所有的

return;

至

return attackFinished;

并改变你调用的所有地方

attackOrSkip(....)

根据方法返回的内容设置攻击已完成

attackFinished = attackOrSkip(....)

或者-你可以在一个Holder (an example of the concept)对象中传入一个额外的参数-- attackFinished --同样，引用不能改变，但是你可以使用attackFinished.value = true (然后，当你退出递归时，它在整个堆栈中都是一样的)。