laravel - 错误异常 : Undefined offset: 0

Question

在我的数组推送上，如果它们具有相同的日期，我想连接 2 个数据

$goal = Goal::where('employee_id',Auth::user()->employees->first()->id)
->with('accomplishments')->orderBy('date','asc')->get();

    $next_week = $goal->whereBetween('date',[$add_start_date,$add_end_date]);
    $last_week = $goal->whereBetween('date',[$sub_start_date,$sub_end_date]);

$goals = [];
$date = "";
        for ($i=0; $i < count($next_week); $i++) { 
                if($next_week[$i]['date']==$date){
                    $goals[$i-1]['activity'] = $goals[$i-1]['activity'] .', '. $next_week[$i]['activity'];
                    continue;
                }
                array_push($goals,$next_week[$i]);
                $date = $next_week[$i]['date'];
    }

Answer 1

在 Laravel 集合上使用过滤时，索引丢失，
要重新索引结果数组，请使用“值”:

 $next_week = $goal->whereBetween('date',[$add_start_date,$add_end_date])->values();
    $last_week = $goal->whereBetween('date',[$sub_start_date,$sub_end_date])->values();