How can I match everything with a regular expression?

Question

preg_match("/^[MYEXPRESSION]+$/i", $anything)

What can I set MYEXPRESSSION to such that the above line always returns true? Nothing outside the MYEXPRESSION character class can be changed.

Answer 1

Doesn't seem possible

preg_match("/^[.]+$/i", $anything)

would need at least one character to match. Changing MYEXPRESSION otherwise like to .]*[. won't help as long as the + sign is there there needs to be at least one character to match.

Answer 2

preg_match("/^[_]?|\]+$/i", $anything)

So EXPRESSION = '_]?|\' , you can replace the _ portion with anything really...

Answer 3

This is not possible. The + quantifier requires at least one character so it won't be able to match the empty string.

Answer 4

You've a + qualifier so that means at least one or more. In other words, it can never be set to not match anything always .

However, you can set MYEXPRESSSION to ^\r\n so that it'll match anything but a newline .