3v4l.org

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<?php $cars = array("A4 1.9tdi (2003-2009)", "A4 2.0tdi (2003-2009)", "Passat B7 1.9tdi(2003-2009)", "Passat B7 2.0 tdi(2003-2010)"); foreach($cars as $key => $car){ $model = explode(' ', $car, 2); $make[$model[0]][] = $car; } $stmt = 'Select a car: <select id="cars">'; foreach($make as $label => $type){ $stmt .= '<optgroup label="'.$label.'">'; foreach($type as $car){ list($t, $c) = explode(' ', $car, 2); $stmt .= '<option name="'.$c.'">'.$c.'</option>'; } $stmt .= '</optgroup>'; } $stmt .= '</select>'; echo $stmt; ?>
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
Select a car: <select id="cars"><optgroup label="A4"><option name="1.9tdi (2003-2009)">1.9tdi (2003-2009)</option><option name="2.0tdi (2003-2009)">2.0tdi (2003-2009)</option></optgroup><optgroup label="Passat"><option name="B7 1.9tdi(2003-2009)">B7 1.9tdi(2003-2009)</option><option name="B7 2.0 tdi(2003-2010)">B7 2.0 tdi(2003-2010)</option></optgroup></select>

preferences:
155.16 ms | 411 KiB | 5 Q