Question

我正在尝试获取Laravel中上传的Excel文件中的总页数。我上传的文件有3张。所以我希望得到$counter = 3的输出。

代码：

$counter=0;
Excel::load($fileDetails['file_path'], function($sheet) use($counter) {
    $sheet->each(function($sheet) use($counter) {
        echo "It works</br>";   
        $counter++;
    });
});
echo $counter; exit;

输出：

It works
It works
It works
0   //-- This is $counter, which is not get incremented. It has to be 3.

Answer 1

use就像传递参数一样。默认值是传递值，因此在函数内部进行的任何修改都不会反映在函数范围之外。

但是，如果您通过引用传递变量，则会反映更改。

将您的代码更新为：

$counter=0;
// add & to have var passed by reference
Excel::load($fileDetails['file_path'], function($sheet) use(&$counter) {
    // add & to have var passed by reference
    $sheet->each(function($sheet) use(&$counter) {
        echo "It works</br>"; 
        $counter++;
    });
});
echo $counter;
exit;

获取Laravel的总页数

1 个答案: