php正则表达式，匹配模式？

Question

I am trying to make a regex that will match this pattern,

Must be 40 characters long,

Must contain only letters and numbers,

Must contain no spaces,

Case insensitive,

So far I have come up with this but it does not work;

/^[0-9a-f]+$/i

Thanks

Answer 1

/^[0-9a-f]{40}$/i

should do the trick. The number in curly brackets defines the number of characters.

Answer 2

Try this regex:

/^[\da-z]{40}$/i

If you really only want the letters af then use:

/^[\da-f]{40}$/i

Answer 3

试试这个： /^[0-9a-z]{40,40}$/i