按不在特定符号之间的符号拆分字符串

Question

I want to split a string by "&" only in cases when "&" is not between "<%" and "%>" symbols. Between that symbols i have special expressions that i want to ignore during the split. Text is considered as special only when it is between two closest "<%" text "%>". It works like this:

<%qwr<%qrw<%tret%>wet%>qwt => only this is scpecial <%tret%>
<%test142%>wqr%>%<%%>qwr%> => only this is <%test142%> and <%%> is special

Examples:

1) my&string=21<%253&124%> <&> && => ['my', 'string=21<%253&124%> <', '> ', '', '']

2) new<%<&%235<%test&gg%>&test&f => ['new<%<', '%235<%test&gg%>', 'test', 'f']

3) a&<%&qwer&>ty%>&af => ['a', '<%&qwer&>ty%>', 'af']

I tried '\\&(?![^<%]*%>)' and (?<!(<%))\\&(?!(%>)) but that works wrong.

Answer 1

I would use a workaround.

1. match all <% & %> and replace it with a special char (in my case _ underscore) so the result is <% _ %>

2. now split the string with & char

3. finaly replace the special char _ back to &

 const mySplit = (mystr) => { const regex = /<%(?!%>).*%>/gm; const matches = mystr.match(regex); const tmpreplace = matches.map(e => e.replace(/&/g,'_')); matches.forEach(e => mystr = mystr.replace(e,tmpreplace)); return mystr.split('&').map(e => e.replace(/_/g,'&')); } console.log(mySplit('my&string=21<%253&124%> <&> &&')); console.log(mySplit('new<%<&%235<%test&gg%>&test&f')); console.log(mySplit('a&<%&qwer&>ty%>&af'));