How to remove duplicate values in PHP loop?

Question

I am using Word Press with Advanced Custom Fields and have a loop to add a field (location) to an Options tag.

There are several posts with the same location, so if I loop normally I get results such as Toronto, Ottawa, Toronto, Montreal, Toronto, Toronto, Montreal, etc. I want it so it only has "Toronto, Ottawa, Montreal".

I tried to add the values to an array, then use array_unique(), but I do not know how to separate the values in the array.

My code -

<?php while( have_posts() ) : the_post(); ?>
    <?php while ( have_rows( 'location_info' ) ) : the_row(); ?>
        <?php $locations[] = get_sub_field( 'location' ); ?>
        <option><?php echo implode('', array_unique($locations)); ?></option>
    <?php endwhile; ?>
<?php endwhile;?>

But this prints

<option>TorontoOttawaMontreal</option>
<option>TorontoOttawaMontreal</option>
<option>TorontoOttawaMontreal</option>

I need it to print

<option>Toronto</option>
<option>Ottawa</option>
<option>Montreal</option>

Don't your <option> tags need a value attribute, e.g. <option value="Montreal">Montreal</option>? — kmoser
– kmoser, Commented Aug 27, 2022 at 20:24
What have you tried to resolve the problem? Where are you stuck? Why not gather all elements first, remove the duplicates, and print the remaining list? — Nico Haase
– Nico Haase, Commented Aug 28, 2022 at 13:09

dqhendricks · Accepted Answer · 2022-08-30 18:07:19Z

1

Added htmlentities and strip tags for security because it seems like this data must be coming from users.

<? foreach( array_unique( $locations ) as $location ) { ?>
    <option value="<?= htmlentities( $location ) ?>"><?= strip_tags( $location ) ?></option>;
<? } ?>

edited Aug 30, 2022 at 18:07

answered Aug 30, 2022 at 18:01

dqhendricks

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Comments

Shoaib Ali · Accepted Answer · 2022-08-29 05:57:15Z

0

You can use in_array() function to check if value exists in array. Try below code snippet.

<select name="field_name">
<?php
$locations = [];
while( have_posts() ) :
    the_post();
    while ( have_rows( 'location_info' ) ) :
        the_row(); 
        $loc = get_sub_field( 'location' );
        if( in_array( $loc, $locations ) ) {
            continue;
        }
        $locations[] = $loc;
        ?>
        <option value="<?php echo esc_attr( $loc ); ?>"><?php echo esc_html( $loc ); ?></option>
    <?php endwhile; ?>
<?php endwhile; ?>
<?php unset( $locations ) ?>
</select>

edited Aug 29, 2022 at 5:57

answered Aug 27, 2022 at 19:52

Shoaib Ali

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4 Comments

Vijay Hardaha Over a year ago

This is wrong, $locations is not defined when you do an if check, and you just echo the $location which is an array, which will bring errors.

Rohit Gupta Over a year ago

where is the select tag ?

Shoaib Ali Over a year ago

@VijayHardaha $locations is an array but $location(singular) is not. I've changed the name to $loc to make it less confusing.

Vijay Hardaha Over a year ago

Ok, This looks ok, I was assuming that get_sub_field( 'location' ) returns an array, but I think, it returns a string then via the loop we create an array as you're doing.

Moishy · Accepted Answer · 2022-08-30 17:57:45Z

0

<?php while( have_posts() ) : the_post(); ?>
    <?php while ( have_rows( 'location_info' ) ) : the_row(); ?>
        <?php $locations[] = get_sub_field( 'location' ); ?>
    <?php endwhile; ?>
<?php endwhile;?>

<?php $locations_options = array_unique($locations); ?>
<select>
    <?php foreach( $locations_options as $location ): ?>
        <option value="<?php echo $location; ?>"><?php echo $location; ?></option>
    <?php endforeach; ?>
</select>

answered Aug 30, 2022 at 17:57

Moishy

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