explode()在空格上，然后使用
[]表示法以数组形式访问结果字符串：
$words = explode(" ", "Community College District");$acronym = "";foreach ($words as $w) { $acronym .= $w[0];}如果您期望多个空格可以分隔单词，请改用
preg_split()
$words = preg_split("/s+/", "Community College District");或者
-,_，例如，如果非空格字符分隔单词（），请同时使用
preg_split()：
// Delimit by multiple spaces, hyphen, underscore, comma$words = preg_split("/[s,_-]+/", "Community College District");
