search for duplicates in array with specific value - php

Question

Hi i need to check an array for users who wrote more then one post. I wanna do that by the user->url because this one is for every user a unique id.
my array looks like:
{
"meta":{
"network":"all",
"query_type":"realtime"
},
"posts":[
{
"network":"facebook",
"posted":"2014-08-16 08:31:31 +00000",
"sentiment":"neutral",
"url":"someURL",
"user":{
"name":"Terance Podolski",
"url":"someURL1",
"image":"someURL"
}
},
{
"network":"facebook",
"posted":"2014-08-16 08:30:44 +00000",
"sentiment":"neutral",
"url":"someURL",
"user":{
"name":"Łukasz Podolski",
"url":"someURL2",
"image":"someURL"
}
},
{
"network":"facebook",
"posted":"2014-08-16 08:25:39 +00000",
"sentiment":"neutral",
"url":"someURL",
"user":{
"name":"Terance Podolski",
"url":"someURL1",
"image":"someURL"
}
}
]
}
first i sort the array two times that i only have posts with positive and neutral sentiment and then for the network that i only have posts from facebook. the code looks like that:
$sentimentPosNeu = array();
$sentimentPosNeuFacebook = array();
foreach ( $myarray -> posts as $post ) {
if($post -> sentiment == 'positive' || $post -> sentiment == 'neutral')
$sentimentPosNeu[] = $post;
}
foreach($sentimentPosNeu as $post) {
if($post -> network == 'facebook')
$sentimentPosNeuFacebook[] = $post;
}
now I need all the users who posted more than one time.
I tried but doesn't work:
$unique = array_unique($sentimentPosNeuFacebook);
$dupes = array_diff_key( $sentimentPosNeuFacebook, $unique );

Answer 1

There are several ways that you could do this, but probably the clearest would be to simply add another looping construct that could group the posts by user url. For example:
$groupedPosts = array();
foreach ($sentimentPosNeuFacebook as $post) {
$userUrl = $post->user->url;
if (!isset($groupedPosts[$userUrl]))
$groupedPosts[$userUrl] = array($post);
else
$groupedPosts[$userUrl][] = $post;
}
This will group the array using the user's url as the grouping key. Then, if you wanted to find, for example, the number of posts per user, you could do the following:
$counts = array_map(function($elem) {
return count($elem);
}, $groupedPosts);
If all you want to do is count the number of posts per user, then #girlwithglasses is definitely the better route. However, if you need to do something more complex, hopefully this gives you something to go on!

Answer 2

If you just want to count the number of positive and neutral posts on Facebook by each user, you can do this:
foreach ( $myarray -> posts as $post ) {
if (($post -> sentiment == 'positive' || $post -> sentiment == 'neutral')
&& $post->network == 'facebook')
$poster[$post->user->url]++;
}
If you wanted to keep the posts themselves, instead of incrementing the count by one each time, you could have $poster[$post->user->url] be an array containing each post by that user -- i.e. replace $poster[$post->user->url]++ with $poster[$post->user->url][] = $post in the code above and use count to get the number of posts.