如何在封闭PHP

Question

我想在上面定义的each函数的闭包中获取一个变量。但返回null：

public function saveSettingsImages(Collection $collection) : array
{
    $arrImages = Array();
    $collection->each(function (UploadedFile $file) use ($arrImages) {
        $filename = $file->store('sliders', ['disk' => 'public']);
        echo $filename; // it prints name of file as well
        array_push($arrImages,$filename);
    });
    dd($arrImages);//it is empty array
    return $arrImages;
}

但是dd($arrImages);为空！

Answer 1

尝试像这样将引用传递给变量

$collection->each(function (UploadedFile $file) use (&$arrImages) {
    $filename = $file->store('sliders', ['disk' => 'public']);
    echo $filename; // it prints name of file as well
    array_push($arrImages,$filename);
});