多维数组-搜索相同的值

Question

I have a multidimensional array which I am looping through using a foreach loop.

I have then need to check whether any of those arrays have the key of 'parent_page' and the same value of any other arrays, such as:

$arrMulti = array(array(
    'page_id' => 1,
    'page_parent' => 28,
    'page_title' => 'Testing'
), array(
    'page_id' => 2,
    'page_parent' => 30,
    'page_title' => 'A seperate page'
), array(
    'page_id' => 3,
    'page_parent' => 28,
    'page_title' => 'Testing Sub Page'
));

So $arrMulti[0]['page_parent'] would match with $arrMulti[2]['page_parent'], so I need to then create a new array using those, something like this:

$arrParentIDs = array( 'parent_id' => array(
    1,
    3
));

Sorry for the poor explanation, but do you have any idea on how to do this?

Thanks!

Answer 1

$parentIds = array();
foreach($arrMulti as $temp):

    if(isset($temp['page_parent'] && !in_array($temp['page_parent'], $parentIds)){
        $parentIds[] = $temp['page_parent'];
    }

endforeach;

var_dump($parentIds);//to show the contents

Answer 2

Try something like this..

foreach($arrMulti as $array) {
    foreach($array as $key=>$val) {
        //your statement/condition
    }
}