[php] Str_replace for multiple items

I had a situation whereby I had to replace the HTML tags with two different replacement results.

$trades = "<li>Sprinkler and Fire      Protection Installer</li>
<li>Steamfitter </li>
<li>Terrazzo, Tile and Marble      Setter</li>";

$s1 =  str_replace('<li>', '"', $trades);

$s2 = str_replace('</li>', '",', $s1);

echo $s2;

result

"Sprinkler and Fire Protection Installer", "Steamfitter ", "Terrazzo, Tile and Marble Setter",