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up vote 0 down vote favorite

Given this array:

Array
(
[0] => Array
    (
        [title] => this is the newest post
        [ssm_featured_post_id] => 70
    )

[1] => Array
    (
        [title] => sdfsfsdf
        [ssm_featured_post_id] => 63
    )

[2] => Array
    (
        [title] => test
        [ssm_featured_post_id] => 49
    )

[3] => Array
    (
        [title] => Hello world!
        [ssm_featured_post_id] => 1
    )

)

What is the most straightforward way to merge another similar array with the new values.

the second array may have new items or deleted items.

I want to preserve the order of the items in the first array and add any new items to the end, and remove any items that are not in the new array

Array
(
[0] => Array
    (
        [title] => sdfsfsdf
        [ssm_featured_post_id] => 63
    )

[1] => Array
    (
        [title] => this is the newest post
        [ssm_featured_post_id] => 70
    )

[2] => Array
    (
        [title] => test
        [ssm_featured_post_id] => 49
    )

[3] => Array
    (

        [title] => Hello world!
        [ssm_featured_post_id] => 1
    )

[4] => Array
    (
        [title] => awesome post
        [ssm_featured_post_id] => 73
    )

)
share|improve this question

3 Answers 3

up vote 1 down vote

You can use the function uasort which allows you to implement your own compare function

function cmp($a, $b) {
    if ($a['ssm_featured_post_id'] == $b['ssm_featured_post_id']) {
        return 0;
    }
    return ($a['ssm_featured_post_id'] < $b['ssm_featured_post_id']) ? -1 : 1; 
}

uasort($array, 'cmp');

In order to remove the duplicated items scan for duplicated item by passing the array

$last_id=-1;
for($i=0; $i < cout($array); $i++){
  if($last_id==$array[$i]['ssm_featured_post_id']){
    unset($array[$i]);//Remove Duplicated Item
  }
  $last_id=$array[$i]['ssm_featured_post_id'];
}
share|improve this answer
    
so do I need to merge the arrays first then run this function? –  paul Oct 30 '12 at 21:55
    
Yes merge them first. $array = array_merge($array1, $array2); uasort($array, 'cmp'); and then $array should be sorted. –  ynh Oct 30 '12 at 21:57
    
that doesn't give me the expected result. It should not have duplicate items VIEW PASTEBIN –  paul Oct 30 '12 at 22:08
    
Updated my post –  ynh Oct 31 '12 at 5:01
up vote 0 down vote

Use array_merge as the keys are numeric. "If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value" http://php.net/manual/en/function.array-merge.php

share|improve this answer
    
I need the intersection of both arrays on the ssm_featured_post_id value, so I do need to only have once the same ssm_featured_post_id in the resulting array –  paul Oct 30 '12 at 21:52
up vote 0 down vote

Well, as I needed to check Array 2 against array 1 and merge in anything new from array 2, this solution seems to work:

$new_values = array_merge( $slides, $featured_posts );
$new_values = array_unique( $new_values, SORT_REGULAR );
share|improve this answer

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