将Java正则表达式转换为php正则表达式

Question

I have a regular expression in Java: [^a-zA-Z0-9.-_]

How to form this regular expression from java to php ?

Answer 1

In php (PCRE) this regular expression looks like

[^a-zA-Z0-9.-_]

_{Yep, it's exactly the same}

Answer 2

it is the same for this particular regex.

But you can make shorter with:

[^\w.-]

and don't forget that the - character must be placed at the last position in a character class

Answer 3

It's exactly the same but you might need to put delimiters around it, eg parenthesis:

([^a-zA-Z0-9._-])

See the little difference moving the minus to the end. That is because [.-_] matches ./0...9:;<=>?@A...Z[\\]^_ . I guess you're not looking for the negation of this as you had already 0-9 and AZ covered.