Building long HTML class names

complex_implode.php

<?php
function build_banner_class(int $age) : array {
  $banner_class = ['banner'];

  if ($age >= 21) {
    $banner_class[]= 'banner--boogie';
  }

  $banner_class = array_merge($banner_class, [
    "color-$color",
    "bg-color-$bg_color",
    "text-$align",
  ]);

  return $banner_class;
}
?>

<div class="<?= implode(' ', build_banner_class(14)) ?>">
  Let's watch some iCarley.
</div>

dumpster_fire.php

<div class="banner color-<?php echo $color; ?> bg-color-<?php echo $bg_color; ?> text-<?php echo $align; ?> pb-<?php if ($padding_bottom) : ?><?php echo $padding_bottom; ?><?php else : ?>pb-0<?php endif; ?>">
  It goes on for days and days...
</div>

implode.php

<div class="<?= implode(' ', [
  'banner',
  "color-$color",
  "bg-color-$bg_color",
  "text-$align",
  'pb-' . $padding_bottom ?: '0',
]) ?>">
  It's so much easier to read a list vertically.
</div>

join.erb

<div class="<%= [
  'banner',
  "color-#{color}",
  "bg-color-#{bg_color}",
  "text-#{align}",
  "pb-#{padding_bottom || '0'}",
].join(' ') %>">
  It is so much easier to read a list vertically.
</div>

join.js

<div className="{[
  'banner',
  `color-${color}',
  `bg-color-${bgColor}',
  `text-${align}`,
  `pb-${paddingBottom ? paddingBottom : '0'}`,
].join(' ')}">
  It is so much easier to read a list vertically.
</div>

poor.php

<div class="banner color-<?= $color ?> bg-color-<?= $bg_color ?> text-<?= $align ?> pb-<? if ($padding_bottom) : ?><?= $padding_bottom ?><? else : ?>pb-0<? endif ?>">
  It goes on for days and days...
</div>