I would recommend you use the literal notation, and the \s character class: There’s a difference between using the character class \s and just ‘ ‘, this will match a lot more white-space characters, for example ‘\t\r\n’ etc.., looking for ‘ ‘ will replace only the ASCII 32 blank space. The RegExp constructor is useful … Read more
For example Regexr I used lookbehind (?<=) and look ahead (?=) so that “This is” and “sentence” is not included in the match, but this is up to your use case, you can also simply write This is(.*)sentence. The important thing here is that you activate the “dotall” mode of your regex engine, so that … Read more
I have this simple code: I don’t know why I am getting the error: ‘expected string or buffer’ Can anyone help?
This should work Matches an optional + at the beginning of the line and digits after it EDIT: As of OP’s request of clarification: 3423kk55 is matched because so it is the first part (3423). To match a whole string only use this instead:
This: or this: do not work for me. So how can I simply remove the parentheses from a text. For example this: to become this:
.*[^a-zA-Z0-9_].* will match the entire input as long as there is a non-alphanumeric/underscore somewhere in the input. [^a-zA-Z0-9_] will match only a single non-alphanumeric/underscore character (most likely the last one, if you’re using the default greedy matching) if it is somewhere in the input. Which one you want depends on the input and what you want to do … Read more
A sample command that exhibits the symptom: sed ‘s/./@/’ <<<$’\xfc’ fails, because byte 0xfc is not a valid UTF-8 char.Note that, by contrast, GNU sed (Linux, but also installable on macOS) simply passes the invalid byte through, without reporting an error. Using the formerly accepted answer is an option if you don’t mind losing support for your true locale (if you’re on a US system … Read more
This can be done in a single String#replace call:
This should do the trick:
As you says in question: I know that to convert a DFA, M to the complement, M`, I just need to swap the initial accepting states and final accepting states. Its not complement, but you are doing something like reverse of a language and regular languages are closure under reversal. Reversal of DFA What is the Reversal Language ? … Read more