PHP foreach over an array of objects

22,882

Solution 1

The error message indicates that you are trying to all the BattleInitiated() method on something that wasn't an object.

Judging from your code, the problem seems to be with this loop, in the BeginBattle() method :

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

Which means $player, at least one in your array, is probably not an object ; maybe it's null, or an array ?


To know more, you should use var_dump to display the content of $this->_players before the loop, just to make sure it contains what you expect it to :

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

If $this->_players doesn't contain what you expect it to (and it probably doesn't !), you'll then have to find out why...


Considering $this->_players is modified by the AddPlayer() method, which adds what it receives to the end of the array, I would bet that AddPlayer() is called at least once without a correct $player as a parameter.

To help with that, you could use var_dump on the $player being added :

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

If that var_dump indicates at least once that $player is not an object (for instance, it's null, or an array, or a string, ...), that's the cause of your Fatal Error.

Solution 2

don't you see it??

it's all because of a small typo:

 $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);

declared: $_P_layerC used: $_p_layerC

correct that and you're good to go

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Joshua Lowry
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Joshua Lowry

An interaction designer who has specialized in Scientific Software Design.

Updated on February 05, 2020

Comments

  • Joshua Lowry
    Joshua Lowry almost 4 years

    I'm trying to use a foreach loop for an array of objects. Inside of the BeginBattle() method I want to iterate through all of the objects and increment their played count automatically. Unfortunately, the web browser shows I have an error: Fatal error: Call to a member function BattleInitiated() on a non-object in /nfs/c05/h01/mnt/70299/domains/munchkinparty.neededspace.net/html/Battle.php on line 75

    Any ideas?

    <?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/>";
            }
        }
    
    }
    ?>
    

    This is where everything is declared and called:

    <?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();
    ?>
    

    The Player Class

        <?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;
            }
    
        }
    
    ?>
    
  • Joshua Lowry
    Joshua Lowry over 13 years
    I added some code above, but the third player, PlayerC, is null once it is added using AddPlayer... any ideas?
  • Joshua Lowry
    Joshua Lowry over 13 years
    I just realized I was adding $PlayerC not $playerC. Your answer helped me find the error. I added a check when a player is added to the battle to see if it is a 'Player'. Now NULL vars and other types will not be added.
  • Pascal MARTIN
    Pascal MARTIN over 13 years
    Glad to see you found what was causing the problem :-) And thanks for explaning it :-)
  • Joshua Lowry
    Joshua Lowry over 10 years
    Thanks for looking back at this. As you will see my comment on the accepted answer stating that the poster's tips helped me to find the typo and also helped me to realize that I needed to validate the entries before adding them.