- strcmp: documentation ( source)
- array_filter: documentation ( source)
- preg_split: documentation ( source)
- usort: documentation ( source)
- strtolower: documentation ( source)
<?php
$x = '
\arccos \cos \csc \exp \ker \limsup \min \sinh
\arcsin \cosh \deg \gcd \lg \ln \Pr \sup
\arctan \cot \det \hom \lim \log \sec \tan
\arg \coth \dim \inf \liminf \max \sin \tanh
';
$x = array_filter(preg_split('/\s+/', $x));
usort($x, function ($a, $b) {
return strcmp(strtolower($a), strtolower($b));
});
foreach ($x as $xx) {
echo $xx, "\n";
}