Search multidimensional array php - php

Question

I have the following multidimensional array.
$arr = array(
0 => array(
'id' => 1,
'title' => 'title1',
'url' => 'http://www.foo.bar/',
'blurb' => 'blurb1',
'custodian' => 'custodia1',
'tags' => 'tag1',
'active' => 'Y',
),
1 => array(
'id' => '2',
'title' => 'title2',
'url' => 'http://www.foo.bar/',
'blurb' => 'blurb2',
'custodian' => 'custodia2',
'tags' => 'tag1,tag2',
'active' => 'Y',
),
2 => array(
'id' => '3',
'title' => 'title3',
'url' => 'http://www.foo.bar/',
'blurb' => 'blurb3',
'custodian' => 'custodia3',
'tags' => 'tag1,tag2,tag3',
'active' => 'Y',
),
);
I need to filter the array so that only the arrays with "tag2" in the tags value are displayed.
I've looked at array_filter but just can't get my head around it.
Here is my attempt but it doesn't work at all. not sure what I'm doing wrong.
$filterArr = array_filter($arr, function($tag) {
return ($tag['tags'] == 'tag2');
});

Answer 1

The simplest way is to use foreach loop and in the body of loop check for 'tag2'
If you need to delete all rows without tag2 in tags you can use next loop:
foreach ($arr as $key => $value) {
if (!preg_match('/\btag2\b/',$value['tags'])) {
unset($arr[$key]);
}
}

Answer 2

you could use array_filter and provide the right callback
$result = array_filter($arr,function($t){
return in_array('tag2',explode(',',$t['tags']));
});

Answer 3

array_filter takes each element of the array and passes it to the specified function, in that function you need to return true or false, true if it should stay in and false if it should be filtered out
Use explode and in_array to check for tag2
$filteredArray = array_filter($arr, "filterTag");
function filterTag($arrayElement) {
return in_array("tag2",explode(",",$arrayElement["tags"]));
}
your attempt does not work because some of your "tags" contain other words than tags2, like tag1,tag2,tag3 doing a simple == comparison does not search a string for another string

Answer 4

$resultArr = array();
foreach($arr as $curr)
{
$tagsData = explode(',',$curr['tags']);
if(in_array('tag1',$tagsData)
$resultArr[] = $curr;
}
$resultArr is the resulting array containing the arrays with tags having tag1