Creating array variable in collection loop

Question

I get data from query and running a foreach loop on it.

foreach($result as $data)
{
    $myVar[$data->flag][$data->year]['totalActions'] += $data->totalActions;
}

And getting this error Undefined variable: myVar

When I create a variable before loop like $myVar = []

Then it gives me the error Undefined index: All

Here All is value of $data->flag

How to handle this?

what is the data type of $data->year (string ?) and $data->totalActions (int ?) ? — Mahmood Ahmad
– Mahmood Ahmad, Commented Mar 2, 2021 at 15:30

Mahmood Ahmad · Accepted Answer · 2021-03-02 16:08:22Z

first of all you need to define $myVar (before foreach) as you did: $myVar = [];

second you need to define/isset $myVar[$data->flag], $myVar[$data->flag][$data->year] and $myVar[$data->flag][$data->year]['totalActions'] inside the foreach

in summery the whole snippet of code will be like so:

$myVar = [];

foreach($result as $data)
{
    $myVar[$data->flag] = isset($myVar[$data->flag]) ? $myVar[$data->flag] : '';
    $myVar[$data->flag][$data->year] = isset($myVar[$data->flag][$data->year]) ? $myVar[$data->flag][$data->year] : '';
    $myVar[$data->flag][$data->year]['totalActions'] = isset($myVar[$data->flag][$data->year]['totalActions']) ? $myVar[$data->flag][$data->year]['totalActions'] : 0;
    $myVar[$data->flag][$data->year]['totalActions'] += $data->totalActions;
}

or simply ignore the the errors by using @ before $myVar so you can do so:

$myVar = [];

foreach($result as $data)
{
    @$myVar[$data->flag][$data->year]['totalActions'] += $data->totalActions;
}

zlodes · Accepted Answer · 2021-03-02 15:14:08Z

1

Just create and init the $myVar before the foreach and init with the zero value if key isn't exists.

$myVar = [];

foreach($result as $data)
{
    if (!isset($myVar[$data->flag][$data->year])) {
        if (!isset($myVar[$data->flag])) {
            $myVar[$data->flag] = [];
        }

        $myVar[$data->flag][$data->year] = ['totalActions' => 0];
    }

    $myVar[$data->flag][$data->year]['totalActions'] += $data->totalActions;
}

answered Mar 2, 2021 at 15:14

zlodes

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