如果找到值，则合并2个数组并创建新值

Question

i want to compare 2 arrays. If a value from $a ist found is $b there should be make a new value in $a like [found] => true.

Array $a:

Array
(
[1] => Array
    (
        [grpID] => 1
        [groupname] => Marketing
    )

[2] => Array
    (
        [grpID] => 2
        [groupname] => Vertrieb
    )

[4] => Array
    (
        [grpID] => 4
        [groupname] => Produktion
    )

)

Array $b:

Array
(
[1] => Array
    (
        [usrID] => 23
        [grpID] => 1
    )

)

So now i want to compare these two.

The result should look like the following, because $b[1]['grpID'] was like in $a[1]['grpID']:

Array $c (or $a as manipulated?):

Array
(
    [1] => Array
    (
        [grpID] => 1
        [groupname] => Marketing
        [found] => true
    )
    [2] => Array
    (
        [grpID] => 2
        [groupname] => Vertrieb
        [found] => false
    )
)

The size of $b may vary so i don't think i can work with a for-loop, can i?

Sorry, i've got no code so far as i don't have an idea how to start.

Thanks in advance.

Best regards

Answer 1

Do it with an temporary array $temp.

$a = array();
$b = array();
$c = array();
$tmp = array();

$a[1] = array('grpID' => 1, 'groupname' => 'Marketing');
$a[2] = array('grpID' => 2, 'groupname' => 'Vertrieb');
$a[4] = array('grpID' => 4, 'groupname' => 'Produktion');

$b[1] = array('usrID' => 23, 'grpID' => 1);

foreach ($b as $key => $value) {
    $tmp[] = $value['grpID'];
}

foreach ($a as $key => $value) {
        $c[] = array_merge($value, array('found' => (in_array($value['grpID'], $tmp) ? 'true' : false)));
}