Using concatenate with WordPress Thumbnail

Hi can someone explain me why the thumbnail is showing outside from the div? am i using the function correctly to concatenate the thumbnail inside the $list. BTW im running this code inside a shortcode that's why i use a concatenate function.

$list = "";
$list = " <div class='box'> ". the_post_thumbnail('post-thumbnail') . "</div>";

Hi can someone explain me why the thumbnail is showing outside from the div? am i using the function correctly to concatenate the thumbnail inside the $list. BTW im running this code inside a shortcode that's why i use a concatenate function.

$list = "";
$list = " <div class='box'> ". the_post_thumbnail('post-thumbnail') . "</div>";

• post-thumbnails

Share Improve this question edited Dec 27, 2018 at 7:38 Krzysiek Dróżdż 25.6k99 gold badges5353 silver badges7474 bronze badges asked Dec 27, 2018 at 6:59 j. Redj. Red 1333 bronze badges 1

• Can you please share the output HTML you are getting for the above – Pratik bhatt Commented Dec 27, 2018 at 7:08

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1 Answer 1

Sorted by: Reset to default 2

the_post_thumbnail function echoes the result and does not return anything.

If you want to concatenate it this way, you should use wp_get_attachment_image instead.

$list .= '<div>'. wp_get_attachment_image( get_post_thumbnail_id(), 'post-thumbnail' ) . '</div>';