转义双引号正则表达式JavaScript

Question

I have a simple question. How can I match any string that is not enclosed in double quotes or/and < and > characters sequences?

Example. I got this link. And I don't want to match it if it is enclosed in double quotes.

((https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])

This doesn't work, by putting [^"] at the beggining and at the end:

([^"](https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|][^"])

Because links that are not enclosed in double quotes will not be matched unless they start with something else than a doule quote.

Answer 1

I wouldn't try to do it in a single RegEx since, as you've noticed, it's probably not going to work.

Assuming you're trying to do something like auto-linking, including optional quotes in your search, then discarding them after, would work:

var re = /"?(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|]"?/gi;
var quoted = /^".+"$/;

var txt = 'A real link: http://www.example.com and a quoted link: "http://www.example.com".';

txt = txt.replace(re, 
            function(str) {
              if (str.match(quoted))
                return str;
              else
                return '<a href="' + str + '">' + str + '</a>';
            }
            );

$('#mydiv').html(txt);

A working example: http://codepen.io/paulroub/pen/nlExh

Answer 2

As Esailija suggested, surrounding your regex with ^ and $ will work. Try this in your console. Here's the regex matching a bare URL:

> ' http://www.something.com '.match(/^((https?|ftp|file)://[-A-Z0-9+&@#/%?=~_|!:,.;]*[-A-Z0-9+&@#/%=~_|])$/i)

[" http://www.something.com ", " http://www.something.com ", "http"]

and here it is not matching a URL embedded in double quotes or angle brackets:

>'" http://www.something.com "'.match(/^((https?|ftp|file)://[-A-Z0-9+&@#/%?=~_|!:,.;]*[-A-Z0-9+&@#/%=~_|])$/i)

null

>'> http://www.something.com <'.match(/^((https?|ftp|file)://[-A-Z0-9+&@#/%?=~_|!:,.;]*[-A-Z0-9+&@#/%=~_|])$/i)

null

Don't pick this answer as I'm just reiterating what Esailija suggested.

Answer 3

It's possible because this works:

<script>

var str='https://test.com/';
var patt=/[^"].*[^"]/g;

var result=patt.test(str);
document.write("Returned value: " +  result); 

str='"http://test.com/"';
result=patt.test(str);
document.write("<br>Returned value: " +  result);

</script>
</body>
</html>

Maybe it's your regexp for the link that is wrong