PHP Regex添加某些字符

Question

I have the following regex that allows any letter and number (and I think uppercase too)! 我有以下允许任何字母和数字的正则表达式（我也认为是大写）！

What I need is to allow certain characters such as a - value and only that. 我需要的是允许某些字符，例如-值，仅此而已。

How would I insert that into this? 我该如何插入呢？

$reg = preg_replace('/[^a-z0-9 ]/i', '', $reg);

Answer 1

You can add additional characters inside the brackets like this: 您可以在方括号内添加其他字符，如下所示：

$reg = preg_replace('/[^a-z0-9 \-]/i', '', $reg);

If you meant that you want the expression inside the brackets or a minus, you can use this: 如果您想将表达式放在方括号内或减号内，则可以使用以下命令：

$reg = preg_replace('/([^a-z0-9 ]|\-)/i', '', $reg);

Not tested, but I think thats it. 未经测试，但我认为就是这样。