如何在Laravel控制器中使用变量？

Question

I as using DataTables in Laravel 5.1 and I want to increment a variable in a function but this is the error.

Undefined variable: index

public function create()
{
    $index = 0;

    return Datatables::of(news::select('news.id as check', 'news.id as number', 'news.title', 'news.body', 'news.hits',
        'news.created_at'))
        ->editColumn('check', function ($row) {
            return '<input type="checkbox" name="checkedBox1[]" value="' . $row->check . '">';
        })
        ->editColumn('number', function ($row) {
            return ++$index;
        })
        ->editColumn('created_at', function ($row) {
            return jDate::forge(strtotime($row->created_at))->format('datetime');
        })
        ->make();
}

Answer 1

You need

    ->editColumn('number', function($row) use (&$index){ return ++$index; })

Instead of

    ->editColumn('number', function($row){ return ++$index; })

The use keyword is to pass closures variables from scope and the & makes it able to edit the original variable