您已经指出，在这种情况下不需要urlencode()，而且trim()也不需要.如果我理解正确，则第4步是避免连续出现多个破折号，但它不会阻止两个以上的破折号.另一方面，连接两个单词的短划线(例如大范围")将被您的解决方案删除，而它们似乎保留在SO上.

As you pointed out already, urlencode() is not needed in this case and neither is trim(). If I understand correctly, step 4 is to avoid multiple dashes in a row, but it will not prevent more than two dashes. On the other hand, dashes connecting two words (like in "large-scale") will be removed by your solution while they seem to be preserved on SO.

我不确定这是否真的是***的方法，但这是我的建议:

I'm not sure that this is really the best way to do it, but here's my suggestion:

$str = strtolower( 
  preg_replace( array('/[^a-z0-9\- ]/i', '/[ \-]+/'), array('', '-'), 
  $urlPart ) );

所以:

1. 删除任何既不是空格，破折号也不是字母数字的字符
2. 用单个破折号替换任何连续数量的空格或破折号
3. strtolower()