删除字符串开头和结尾的方括号

Question

I would like to remove square brackets from beginning and end of a string, if they are existing.

[Just a string]
Just a string
Just a string [comment]
[Just a string [comment]]

Should result in

Just a string
Just a string
Just a string [comment]
Just a string [comment]

I tried to build an regex, but I don't get it in a correct way, as it doesn't look for the position:

string.replace(/[\[\]]+/g,'')

Answer 1

string.replace(/^\[(.+)\]$/,'$1')

should do the trick.

• ^ matches the begining of the string
• $ matches the end of the string.
• (.+) matches everything in between, to report it back in the final string.

Answer 2

Probably a better reg exp to do it, but a basic one would be:

 var strs = [ "[Just a string]", "Just a string", "Just a string [comment]", "[Just a string [comment]]" ]; var re = /^\\[(.+)\\]$/; strs.forEach( function (str) { var updated = str.replace(re,"$1"); console.log(updated); }); 

Reg Exp Visualizer

Answer 3

Blue112 provided a solution to remove [ and ] from the beginning/end of a line (if both are present).

To remove [ and ] from start/end of a string (if both are present) you need

input.replace(/^\[([\s\S]*)]$/,'$1')

or

input.replace(/^\[([^]*)]$/,'$1')

In JS, to match any symbol including a newline, you either use [\\s\\S] (or [\\w\\W] or [\\d\\D] ), or [^] that matches any non-nothing .

 var s = "[word \\n[line]]"; console.log(s.replace(/^\\[([\\s\\S]*)]$/, "$1"));