Invalid regular expression:Lone quantifier brackets - regex

Question

I have a html phone pattern that will accept these formats :
+61 x xxxx xxxx,
+61xxxxxxxxx,
0x xxxx xxxx,
0xxxxxxxxx,
xxxx xxxx,
xxxxxxxx,
+xx xxx xxx xxx,
+xxxxxxxxxxx,
0xxx xxx xxx,
0xxxxxxxxx
It was working few months ago, now suddenly my phone fields are not validating . I'm having this error:
Pattern attribute value ^(?:0|\(?\+61\)?\s?|0061\s?)[1-79](?:[\.\-\s]?\d\d){4}|(\d{4}[\s]\d{4})|(\d{8})|(\d{4}[\s]\d{3}[\s]\d{3})|(\+61\[\s]\d{3}[\s]\d{3}[\s]\d{3})|(\+61\s\d{3}\s\d{3}\s\d{3})$ is not a valid regular expression: Uncaught SyntaxError: Invalid regular expression: /^(?:0|\(?\+61\)?\s?|0061\s?)[1-79](?:[\.\-\s]?\d\d){4}|(\d{4}[\s]\d{4})|(\d{8})|(\d{4}[\s]\d{3}[\s]\d{3})|(\+61\[\s]\d{3}[\s]\d{3}[\s]\d{3})|(\+61\s\d{3}\s\d{3}\s\d{3})$/: Lone quantifier brackets

Answer 1

So far, no one cared to show where in your pattern the error is.
…|(\+61\[\s]\d{3}[\s]\d{3}[\s]\d{3})|(\+61\s\d{3}\s\d{3}\s\d{3})$
^
There by mistake you inserted a backslash, escaping the opening bracket, so making it an ordinary character and leaving the closing bracket Lone. (Sadly the error message is somewhat misleading, since those brackets are of course not quantifier brackets.)

Answer 2

Similar to the request above, I received the error in Visual Studio Code using the following RegEx to capture words wrapped in brackets:
\[([^\\[\r\n]*(?:\\.[^\\]\r\n]*)*)\] (which is incorrect)
on the text string (SQL)
SELECT d.[fname]
,d.[lname],d.[address1],d.[address2],d.[City],d.[zip]
FROM my_table d
WHERE [hh_id] IN (SELECT [HhId]
FROM other_table)
However using this RegEx pattern in online regex tools shown in https://regex101.com/r/HGycR9/1 show it is valid RegEx.
The correct RegEx pattern is \[([^[\r\n]*(?:\\.[^\r\n]*)*)\], which will highlight:
SELECT d.[fname] ,d.[lname],d.[address1],d.[address2],d.[City],d.[zip]
FROM my_table d WHERE [hh_id] IN (SELECT [HhId] FROM other_table)
Then you can use $1 in the replace field of VS Code to remove the brackets and leave the words contained within them.
SELECT d.fname
,d.lname,d.address1,d.address2,d.City,d.zip
FROM my_table d
WHERE hh_id IN (SELECT HhId
FROM other_table)

Answer 3

Just to spell it out a bit more explicitly, the difference between VSCode (and apparently Visual Studio) and other Java/ECMAScript regex interpreters is that the VS products are picky about matching brackets, even if they should be interpreted as literal characters.
For example, the regex below - with just the first bracket escaped - is fine with matching a string surrounded by square brackets in most JS-based (and PCRE) regex interpreters. e.g.: [string]
\[\w+]
^
While just the "opening" square bracket is escaped, the "closing" square bracket is also interpreted as a literal character. Semantically, with the first bracket escaped, you haven't actually started a character class match (or group or quantifier, if it's parentheses () or curly braces {} you're matching).
In VSCode, you must also escape the "closing" bracket, or else you get the "Lone quantifier brackets" error.
\[\w+\]
^ ^
Another irritating aspect is that the .NET regex interpreter behaves very similarly to a standard Javascript interpreter, so it similarly does not care about escaping both brackets if the opening one is escaped. Something of this nature that's fine in .NET or Powershell won't work the same in VSCode.

Answer 4

That means exactly that, pattern invalid.
If you want to match phones from Australia, you could use:
pattern="^(?:0|\(?\+61\)?\s?|0061\s?)[1-79](?:[\.\-\s]?\d\d){4}$"
Pattern found here.
Example:
https://jsfiddle.net