PHP foreach通过一系列对象

Question

我正在尝试对一组对象使用foreach循环。 在BeginBattle（）方法内部，我想遍历所有对象并自动增加其播放计数。 不幸的是，Web浏览器显示我有一个错误： 致命错误：在/nfs/c05/h01/mnt/70299/domains/munchkinparty.neededspace.net/html/Battle中的非对象上调用成员函数BattleInitiated（） .php行75

有任何想法吗？

<?php
/* 
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 * Description of Battle
 *
 * @author joshualowry
 */
class Battle {
    /**
     *
     * @var <type>
     */
    private $_players;
    /**
     *
     * @var <type>
     */
    private $_battleInProgress;
    /**
     *
     */
    public function Battle(){
        $this->_players = array();
        $this->_battleInProgress = FALSE;

    }
    /**
     *
     * @param <type> $player
     * @return <type>
     */
    public function AddPlayer($player){
        if(!$this->_battleInProgress)
            $this->_players[] = $player;
        else
            return;
            //Spit some error
    }

    /**
     *
     * @param <type> $player
     * @return <type>
     */
    public function BattleWon($player){
        if($player != NULL)
            $player->BattleWon();
        else
            return;
            //Spit some error
    }
    /** GetPlayerByName Get the player's object by the player's name field.
     *
     * @param <type> $playerName
     * @return <type>
     */
    public function GetPlayerByName($playerName){
        foreach($this->_players as &$player) {
            if($player->GetName() == $playerName)
        return $player;
        }
        return NULL;
    }

    /**
     *
     */
    public function BeginBattle(){
        $this->_battleInProgress = TRUE;
        foreach($this->_players as $player){
        $player->BattleInitiated();
    }
    }
    /**
     *
     */
    public function DisplayCurrentBoard() {
        echo "Name  Alias   Wins    Battles<br/>";
        foreach($this->_players as &$player){
            echo "$player->GetName()    $player->GetAlias() $player->GetWins()  $player->GetBattles()<br/>";
        }
    }

}
?>

在这里声明和调用所有内容：

<?php
    include 'Battle.php';
    include 'Person.php';
    include 'Player.php';

    $currentBattle = new Battle();

    $playerA = new Player("JohnnyDanger","John",0,0);
    $playerB = new Player("JoshTheJest","Josh",0,0);
    $PlayerC = new Player("CarbQueen","Nicole",0,0);

    $currentBattle->AddPlayer($playerA);
    $currentBattle->AddPlayer($playerB);
    $currentBattle->AddPlayer($playerC);

    $currentBattle->BeginBattle();
    $currentBattle->BattleWon($currentBattle->GetPlayerByName("Josh"));
    $currentBattle->DisplayCurrentBoard();
?>

玩家阶层

    <?php

    /**
    * Description of Player
    *
    * @author joshualowry
    */
    class Player extends Person {

        private $_alias;
        private $_wins;
        private $_battles;

        public function Player($name, $alias, $wins, $battles) {
            parent::SetName($name);
            $this->_alias = $alias;
            $this->_battles = $battles;

            if($battles == 0) {
                $this->_wins = 0;
            }
            else {
                $this->_wins = $wins;
            }
        }

        protected function SetAlias($value){
            $this->_alias = $value;
        }

        public function GetAlias(){
            return $this->_alias;
        }

        protected function SetBattles($value) {
            $this->_battles = $value;
        }

        public function GetBattles(){
            return $this->_battles;
        }

        protected function SetWins($value) {
            $this->_wins = $value;
        }

        public function GetWins() {
            return $this->_wins;
        }

        public function BattleWon(){
            $this->_wins += 1;
        }

        public function BattleInitiated(){
            $this->_battles += 1;
        }

    }

?>

Answer 1

该错误消息表明您正在尝试对不是对象的某些对象使用所有BattleInitiated()方法。

从您的代码来看，问题似乎出在BeginBattle()方法中的此循环中：

foreach($this->_players as $player){
    $player->BattleInitiated();
}

这意味着$ player，可能在您的数组中至少一个不是对象； 也许它为null或数组？

要了解更多，您应该使用var_dump在循环之前显示$this->_players var_dump $this->_players的内容，只是要确保它包含您期望的内容：

public function BeginBattle(){
    var_dump($this->_players);
    $this->_battleInProgress = TRUE;
    foreach($this->_players as $player){
        $player->BattleInitiated();
    }
}

如果$this->_players不包含您期望的内容（并且可能不包含！） ，则必须找出原因...

考虑到$this->_players AddPlayer() $this->_players是由AddPlayer()方法修改的，该方法会将接收到的内容添加到数组的末尾，因此我敢打赌，至少在没有正确的$player作为参数的情况下，调用AddPlayer()至少一次。

为了解决这个问题，您可以在要添加的$player上使用var_dump ：

public function AddPlayer($player){
    var_dump($player);
    if(!$this->_battleInProgress)
        $this->_players[] = $player;
    else
        return;
        //Spit some error
}

如果该var_dump至少一次表明$player不是对象（例如，它为null ，数组或字符串，...） ，则这是导致致命错误的原因。

Answer 2

你没看到吗？

都是因为打错字了：

 $playerA = new Player("JohnnyDanger","John",0,0);
    $playerB = new Player("JoshTheJest","Josh",0,0);
    $PlayerC = new Player("CarbQueen","Nicole",0,0);

    $currentBattle->AddPlayer($playerA);
    $currentBattle->AddPlayer($playerB);
    $currentBattle->AddPlayer($playerC);

声明：$ _P_layerC使用：$ _p_layerC

改正它，你很好

Answer 3

您的$player变量为null或不是您想要的类型的Object 。

PlayerObject是您的播放器类别名称。

例如

$battle=new Battle();
$player1=new PlayerObject();
$player2="player";
$battle->AddPlayer($player1);
$battle->AddPlayer($player2);
$battle->BeginBattle();

当您调用BeginBattle() ， $player1->BattleInitiated(); 将成功，但$player2->BattleInitiated()将给您致命错误并停止代码运行。 如果$player2为null，整数或不是PlayerObject东西，则PlayerObject 。