Remove duplicate from foreach loop

Question

I'm trying to loop through a custom post type and display all meta values for a meta key.

I'm able to display all the values, however there are some duplicates. I want to remove those duplicates.

I have tried using array_unique without luck.

My code:

<?php
query_posts(array(
'post_type' => 'lejlighed'

 ));
 ?>
               <?php
while (have_posts()):
the_post();


$meta = get_post_meta($post->ID, 'antal_varelser');

foreach ($meta as $m) {

    echo '<option value="1">' . $m . '</option>';

}
endwhile;
?>

The result: 2 2 3 4 3 3 4

My code with array_unique:

<?php
$the_query = new WP_Query(array(
'post_type' => 'lejlighed',
 ));
 ?>
 <?php

 while ($the_query->have_posts()):
 $the_query->the_post();
 $meta = get_post_meta($post->ID, 'antal_varelser');
 $result = array_unique($meta);

 foreach($result as $r)
 {
 echo '<option value="1">' . $m . '</option>';
 }

 endwhile; ?>

Outputs nothing.

print_r($meta) returns:

Array ( [0] => 2 ) Array ( [0] => 12 ) Array ( [0] => 4 ) Array ( [0] => 2 ) Array ( [0] => 5 ) Array ( [0] => 2 ) Array ( [0] => 4 ) Array ( [0] => 4 ) Array ( [0] => 3 ) Array ( [0] => 3 )

Any suggestions?

What was you code with `array_unique`? Have you tried to use an `in_array` to only add items which are not there? — bear, Aug 11 '14 at 15:36
By looking at this code, I think you're querying and having duplicates. Maybe your query is wrong? — Vernard Luz, Aug 11 '14 at 15:39
[This](http://stackoverflow.com/questions/10408482/how-to-get-unique-value-in-multidimensional-array) seems like your solution — vch, Aug 11 '14 at 15:39
The query should be right, because i need the value from all of my posts. Some of them are duplicate - them I need to get rid of. — Karsten Tietje, Aug 11 '14 at 15:45

Tibor B. · Answer 1 · 2014-08-11T15:57:17.613

3

array_unique should work.

$result = array_unique($meta);
foreach ($result as $m) {
  echo '<option value="1">' . $m[0] . '</option>';
}

If not, then...

$temp = array();
foreach ($meta as $m) {
  if (!in_array($m[0], $temp)) {
    echo '<option value="1">' . $m[0] . '</option>';
    $temp[] = $m[0];
  }
}

edited Aug 11 '14 at 15:57

answered Aug 11 '14 at 15:43

Tibor B.

1,680
1
10
12

I tried the first solution myself without luck. The second solution doesn't do the job either. – Karsten Tietje Aug 11 '14 at 15:47
Can you please provide the results you get for `print_r($meta);`? – Tibor B. Aug 11 '14 at 15:52
Still returns duplicate values. – Karsten Tietje Aug 11 '14 at 16:02
Either of these literally cannot return duplicate values mate. – Tibor B. Aug 11 '14 at 16:12
Tested both of these here: http://sandbox.onlinephpfunctions.com/code/bc1f4791b0a47ab93cf83af36583134d4546560a – Tibor B. Aug 11 '14 at 16:12
Hmm i will investigate further. – Karsten Tietje Aug 11 '14 at 16:13

nouseforname · Answer 2 · 2014-08-11T17:20:37.537

You could try to use a loop and fill another array first with:

bool in_array ( $needle , array $haystack)

Then you should have only unique values in the new array, which can be used for ur loop

Edit:

For me two ways are working...

We assume this array is given:

$org = array('1', '2', '2', '3', '3', '4', '5', '6');

Simple array_unique:

// simple array unique call with sort by string
$new = array_unique($org, SORT_STRING);

// output the sorted array
var_dump($new);

Sort array in loop by using in_array:

// sort with in_array()
for ($i=0; $i < count($org); $i++) {

    if (!in_array($org[$i], $new)) {
        $new[] = $org[$i];
    }
}

// output the sorted array
var_dump($new);

Live Demo

@Karsten I added two different sample code for you incl live demo — nouseforname, Aug 11 '14 at 17:22

score 0 · Answer 3 · edited May 23 '17 at 12:24

array_unique seems to work.

<?php
$a = array (
    '1', '2', '2', '3', '4', '5', '4'
);
echo "<pre>initial array\n";
print_r($a);
echo "\n";

$result = array_unique($a);

echo "array_unique\n";
print_r($result);
echo "\n</pre>";
?>

Produces:

initial array
Array
(
    [0] => 1
    [1] => 2
    [2] => 2
    [3] => 3
    [4] => 4
    [5] => 5
    [6] => 4
)

array_unique
Array
(
    [0] => 1
    [1] => 2
    [3] => 3
    [4] => 4
    [5] => 5
)

Can you provide additional detail? That might help us help you.

EDIT: After seeing the output of print_r, this solution should work for you:

<?php
$multi_a = array (
    array (
        '1'
    ),
    array (
        '2'
    ),
    array (
        '3'
    ),
    array (
        '4'
    ),
    array (
        '4'
    ),
    array (
        '5'
    ),
    array (
        '2'
    )
);
echo "<pre>initial multi-dimensional array\n";
print_r($multi_a);
echo "\n";

$result = array_map("unserialize", array_unique(array_map("serialize", $multi_a)));

echo "removed duplicates in multi-dimension array\n";
print_r($result);

echo "\n</pre>";
?>

Output:

initial multi-dimensional array
Array
(
    [0] => Array
        (
            [0] => 1
        )

    [1] => Array
        (
            [0] => 2
        )

    [2] => Array
        (
            [0] => 3
        )

    [3] => Array
        (
            [0] => 4
        )

    [4] => Array
        (
            [0] => 4
        )

    [5] => Array
        (
            [0] => 5
        )

    [6] => Array
        (
            [0] => 2
        )

)

removed duplicates in multi-dimension array
Array
(
    [0] => Array
        (
            [0] => 1
        )

    [1] => Array
        (
            [0] => 2
        )

    [2] => Array
        (
            [0] => 3
        )

    [3] => Array
        (
            [0] => 4
        )

    [5] => Array
        (
            [0] => 5
        )

)

Taken from https://stackoverflow.com/a/946300/720829 HTH

Remove duplicate from foreach loop

3 Answers3