javascript - js regular matching problem

Question

I would like to ask you where I made a mistake. Why is there no "[b]php5[/b]" and "[b]php4[/b]" that I want?

Answer 1

/(\[[a-z]\])(\w*)(\[\/[a-z]\])/g

Thank you everyone, I wrote it down

Answer 2

/([[w]])(w*)([/[w]])/g Just finished writing, str.replace(re,function(str,$1,$2,$3){ return str;}) like this Write clearly