数组的键作为函数php中的参数

Question

I try to pass a key of an array in parameter in my function like that

function getStats($array , $key){

    $data = array_sum(array_map(function($item) { 
        return $item[$key]; 
    }, $array));

    return $data;
}

$stats = getStats($myarray , 'nb_view');

It doesn't work but this works

function getStats($array){

    $data = array_sum(array_map(function($item) { 
        return $item['nb_view']; 
    }, $array));
    return $data;
}

$stats = getStats($array);

Answer 1

When defining your anonymous function, the use keyword allows you to inherit variables from the parent scope.

function getStats($array , $key){

    $data = array_sum(array_map(function($item) use($key) { 
        return $item[$key]; 
    }, $array));

    return $data;
}