如果数组不存在，则向数组添加键和值

Question

So I have an Array called $sales that consits of objects like:

"DR22" => array:3 [▼
    "brand" => "DR22"
    "year" => "0"
    "last_year" => null
  ]
  "FGIPA46C" => array:3 [▼
    "brand" => "FGIPA46C"
    "month" => "3"
    "year" => "3"
  ]

Now each one should have "Month" "Year" "Last Year" "Last Month" but if there is no sale its not in there, which i get, but if it doesnt exist I just want to add it with 0 value. I tried:

    foreach ($sales as $sale)
    {  
        if (empty($sale['month'])) {
            $sale['month'] = 0;
        }
    }

But it doesnt add anything. Spits out the same.

Answer 1

foreach ($sales as &$sale) {if (empty($sale['month']))        { $sale['month'] = 0; }}

You need to pass the $sale array by reference (using the &). This will mean that the original $sales array is updated