JS Regex - non capture optional quotes-CodePudding

Struggling getting a working regex that doesn't capture quotes which are optional.

Code and jsfiddle below.

var txt = `#VER B 2000 20190403 "Text" 20190413`; //without quote 2000
var txt2 = `#VER B "2000" 20190403 "Text" 20190413`; //with qutoe 2000

var myRegexp = /(#VER)\s "(. )"|(. )\s (. ?)\s (\d{8})\s "(. )"/g;

do {
    var match = myRegexp.exec(txt2);
    if (match != null)
    {
        match.forEach(function(value) {
        console.log(value);
    });
    //console.log(match);
  }
} while (match != null);

Gives a result with quoted values for txt2.

CodePudding user response：

You can use

var myRegexp = /(#VER.*?)\s (?:"([^"]*)"|(\S ))\s (\d{8})\s "([^"]*)"/g;

See the regex demo. Details:

(#VER.*?) - Group 1: #VER and then any zero or more chars, other than line break chars, as few as possible
\s - one or more whitespaces
(?:"([^"]*)"|(\S )) - either ", then any zero or more chars other than " (captured into Group 2), or one or more non-whitespace chars (captured into Group 3),
\s - one or more whitespaces
(\d{8}) - Group 4: eight digits
\s - one or more whitespaces
"([^"]*)" - ", then any zero or more chars other than " (captured into Group 5), and then a " char.

See the JavaScript demo:

var txt = `#VER B 2000 20190403 "Text" 20190413`;
var txt2 = `#VER B "2000" 20190403 "Text" 20190413`;

var myRegexp = /(#VER.*?)\s (?:"([^"]*)"|(\S ))\s (\d{8})\s "([^"]*)"/g;

for (var txt of [txt, txt2]) {
  do {
    var match = myRegexp.exec(txt);
    if (match != null)
    {
        console.log(txt, '=>',
             [match[1], match[3] || match[2], match[4], match[5]]);
    }
  } while (match != null);
}

CodePudding user response：

Its difficult to determine if a positional way points are intended or
a field delimiter.
Its my guess its actually a hybrid of both.

In that case a simple matching an optional quote on both sides of a
field and outside of the capture should do the trick.

/(\#VER.*)[ \t] "?(. ?)"?[ \t] (\d{8})[ \t] "(. )"/

https://jsfiddle.net/Lj4rzo2s/

 ( \#VER .* )                  # (1)
 [ \t]  
 
 "?
 ( . ? )                       # (2)
 "?
 [ \t]  
 
 ( \d{8} )                     # (3)
 [ \t]  
 
 "
 ( .  )                        # (4)
 "