In your sample $lien
contains the <br>
in the string, whereas $lien2
only contains the link string and not the <br>
.
If you do this it should return true:
$lien = get_field('fieldName');
echo $lien.'<br/>';
$lien2 = 'http://link.com';
echo $lien2.'<br/>';
if($lien2==$lien):
echo "same";
else:
echo "not same";
endif;