Question

我对这个问题感到非常难过，我已经尝试了很多测试来确定问题的根源。在我的Controller中，我为$players数组分配了许多值。当我删除变量opprank时，一切正常。但是当我收到它时，我收到错误消息

未定义属性：stdClass :: $ opprank

我尝试转储$players的值，其中opprank值显示为预期值。我已经尝试将其设置为静态值＆＃39; 10＆＃39;而不是DB值但收到相同的错误。希望有人能发现我出错的地方......

SystemController.php

            foreach ($teams as $team)
            {
                if ($players[$key]->team == $team->id)
                {
                    // Replace Team ID with Team Short Code for Display Purposes
                    $players[$key]->team = $team->code;

                    $matchups = DB::table('schedule')->where('week', $week->value)->get();

                    foreach ($matchups as $matchup)
                    {
                        if ($team->id == $matchup->home_team)
                        {
                            $opp = DB::table('teams')->select('code', 'rank')->where('id', $matchup->away_team)->first();

                            $players[$key]->opponent = $opp->code;
                            $players[$key]->opprank = $opp->rank;
                            $players[$key]->status = 'Home';
                        }
                        else if ($team->id == $matchup->away_team)
                        {
                            $opp = DB::table('teams')->select('code', 'rank')->where('id', $matchup->home_team)->first();

                            $players[$key]->opponent = $opp->code;
                            $players[$key]->opprank = $opp->rank;
                            $players[$key]->status = 'Away';
                        }
                    }
                }
            }

            foreach ($positions as $position)
            {
                if ($players[$key]->position == $position->id)
                {
                    $players[$key]->position = $position->short_name;
                }
            }
        }

        return $players;
    }
}

players.blade.php

                    <table class="table table-striped table-bordered table-hover" id="dt-players-all">
                        <thead>
                            <tr>
                                <th>Position</th>
                                <th>Player</th>
                                <th>Team</th>
                                <th>Opponent</th>
                                <th>Game</th>
                                <th>Opp. Rank</th>
                                <th>FPPG</th>
                                <th>Salary</th>
                            </tr>
                        </thead>
                        <tbody>

                            @foreach ($players as $player)

                                <tr>
                                    <td>{{$player->position}}</td>
                                    <td>{{$player->name}} <font color="red"><b>{{$player->injury_status}}</b></font></td>
                                    <td>{{$player->team}}</td>
                                    <td>{{$player->opponent}}</td>
                                    <td>{{$player->status}}</td>
                                    <td class="center">

                                        @if ($player->opprank <= 10)
                                            <font color="red"><b>{{$player->opprank}}</b></font>
                                        @elseif ($player->opprank > 10 && ($player->opprank <= 20))
                                            <b>{{$player->opprank}}</b>
                                        @else
                                            <b><font color="green">{{$player->opprank}}</font></b>
                                        @endif

                                    </td>
                                    <td class="center">{{$player->fppg}}</td>
                                    <td class="center">${{$player->salary}}</td>
                                </tr>

                            @endforeach

                        </tbody>
                    </table>

Answer 1

在获得$key之后将其初始化为NULL值或某个值 - 我认为它应该位于问题中看不到的某个foreach（）循环中。

$players[$key]->opprank = NULL;

我认为您收到此错误是因为您在某些条件下设置了opprank的值，如果条件未执行则无法分配。如果它只是一个警告，请以这种方式分配。

另外尝试添加else部分（如果这样做 - 将是最好的修复）

if () {
  // your code
}
else if () {
  // your code
}
else {
  $players[$key]->opprank = NULL;
}

在最后一次尝试中，您显然可以对它们执行isset（）或！empty（）检查。只有你的输出很好，你只想摆脱警告。

if(isset($player->opprank)) {
  // existing code for if, else if and else
}

Answer 2

foreach ($matchups as $matchup)
                {
                    if ($team->id == $matchup->home_team)
                    {
                        $opp = DB::table('teams')->select('code', 'rank')->where('id', $matchup->away_team)->first();

                        $players[$key]->opponent = $opp->code;
                        $players[$key]->opprank = $opp->rank;
                        $players[$key]->status = 'Home';
                    }
                    else if ($team->id == $matchup->away_team)
                    {
                        $opp = DB::table('teams')->select('code', 'rank')->where('id', $matchup->home_team)->first();

                        $players[$key]->opponent = $opp->code;
                        $players[$key]->opprank = $opp->rank;
                        $players[$key]->status = 'Away';
                    }
                     else{
                    $players[$key]->opprank = NULL;
                   }
                }

Laravel Undefined属性：stdClass :: $ opprank

2 个答案: