Hi there,

The answer is that the [^a] phrase means any character other than 'a', but it still must match one character. Since the string 'at' only has 2 characters, there is no character at all to match.

So what is actually called for is a negative-lookbehind: /(?<!a)at/ that ensures 'at' isn't preceded by an 'a' character, it will still match 'at' when it begins in the first character position of a string.

/[^a]?at/ Would behave as you expected the original regex to behave. Update: ugh, this was a little optimistic, it will do the wrong thing with 'aat' now.

In reply to Re: little regex question by Loops
in thread little regex question by anaconda_wly

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