Access PHP array element with a function?

15
votes

I'm working on a program that uses PHP's internal array pointers to iterate along a multidimensional array. I need to get an element from the current row, and I've been doing it like so:

$arr[key($arr)]['item']

However, I'd much prefer to use something like:

current($arr)['item'] // invalid syntax

I'm hoping there's a function out there that I've missed in my scan of the documentation that would enable me to access the element like so:

getvalue(current($arr), 'item')

or

current($arr)->getvalue('item')

Any suggestions?

5
phparrays
You have already found the best solution: $arr[key($arr)]['item'] - Bill Karwin
The getvalue approach would be useful even of single-dimmensional arrays too. It would allow to workaroung the ≤5.3 syntax limitations and allowing to access an element from an array, say returned by a function call, directly within one statement. I’m missing such internal function. - Glutexo

5 Answers

12
votes

I very much doubt there is such a function, but it's trivial to write

function getvalue($array, $key)
{
  return $array[$key];
}

Edit: As of PHP 5.4, you can index array elements directly from function expressions, current($arr)['item'].

1
votes

Have you tried using one of the iterator classes yet? There might be something in there that does exactly what you want. If not, you can likely get what you want by extending the ArrayObject class.

0
votes

This function might be a bit lenghty but I use it all the time, specially in scenarious like:

if (array_key_exists('user', $_SESSION) === true)
{
    if (array_key_exists('level', $_SESSION['user']) === true)
    {
        $value = $_SESSION['user']['level'];
    }

    else
    {
        $value = 'DEFAULT VALUE IF NOT EXISTS';
    }
}

else
{
    $value = 'DEFAULT VALUE IF NOT EXISTS';
}

Turns to this:

Value($_SESSION, array('user', 'level'), 'DEFAULT VALUE IF NOT EXISTS');

Here is the function:

function Value($array, $key = 0, $default = false)
{
    if (is_array($array) === true)
    {
        if (is_array($key) === true)
        {
            foreach ($key as $value)
            {
                if (array_key_exists($value, $array) === true)
                {
                    $array = $array[$value];
                }

                else
                {
                    return $default;
                }
            }

            return $array;
        }

        else if (array_key_exists($key, $array) === true)
        {
            return $array[$key];
        }
    }

    return $default;
}

PS: You can also use unidimensional arrays, like this:

Value($_SERVER, 'REQUEST_METHOD', 'DEFAULT VALUE IF NOT EXISTS');
-1
votes

If this does not work, how is your multidimensional array composed? A var_dump() might help.

$subkey = 'B';
$arr = array(
    $subkey => array(
        'AB' => 'A1',
        'AC' => 'A2'
    )
);


echo current($arr[$subkey]);
next($arr[$subkey]);
echo current($arr[$subkey]);
-1
votes

I often use

foreach ($arr as $key=>$val) {
   $val['item'] /*$val is the value of the array*/
   $key         /*$key is the key used */
}

instead of

next($arr)/current($arr)