ErrorException（E_NOTICE）未定义变量：actualLabels

Question

帮助，我的代码中出现错误“ErrorException (E_NOTICE) Undefined variable: actualLabels”$title = "Data Confusion Matrix";$testing_data = DataTesting::count();$klasifikasi = Klasifikasi::with('sentimen')->get();foreach($klasifikasi as $kelas){    $predictedLabels[] = $kelas->sentimen->kategori;    $testing = DataTesting::where('id_testing',$kelas->id_testing)->first();    $twitter = TwitterStream::with('sentimen')->where('id_crawling',$testing->id_crawling)->first();    $actualLabels[] = $twitter->sentimen->kategori; } $getPrecision = new ControllerConfusionMatrix($actualLabels, $predictedLabels); $accuracy = ControllerConfusionMatrix::score($actualLabels, $predictedLabels); $recall = $getPrecision->getRecall(); $precision = $getPrecision->getPrecision();

Answer 1

将此行添加到代码的开头：$actualLabels = []; 您收到错误，因为当$klasifikasi为空时，则不会执行循环内的语句。所以$actualLabels没有创建变量。在这种情况下，您会得到(E_NOTICE) Undefined variable: actualLabels. 希望你能理解。

Answer 2

定义Array()

$predictedLabels = array();

$actualLabels = array();

            foreach($klasifikasi as $kelas){

                $predictedLabels[] = $kelas->sentimen->kategori;

                $testing = DataTesting::where('id_testing',$kelas->id_testing)->first();

                $twitter = TwitterStream::with('sentimen')->where('id_crawling',$testing->id_crawling)->first();

                $actualLabels[] = $twitter->sentimen->kategori;

            }