最简单的方法是使用 explode :

The easiest would be to use explode:

$words = explode(' ', $str);

但这只接受固定的分隔符. split 和 preg_split 确实接受正则表达式，以便您的单词可以用多个空格分隔:

But that does only accept fixed separators. split an preg_split do accept regular expressions so that your words can be separated by multiple spaces:

$words = split('\s+', $str);
// or
$words = preg_split('/\s+/', $str);

现在，您还可以使用 trim :

Now you can additionally remove leading and trailing spaces with trim:

$words = preg_split('/\s+/', trim($str));