Regular Expression to find a string included between two characters while EXCLUDING the delimiters

Question

I need to extract from a string a set of characters which are included between two delimiters, without returning the delimiters themselves.

A simple example should b

Answer 1

If you are using JavaScript, the solution provided by cletus, (?<=\[)(.*?)(?=\]) won't work because JavaScript doesn't support the lookbehind operator.

Edit: actually, now (ES2018) it's possible to use the lookbehind operator. Just add / to define the regex string, like this:

var regex = /(?<=\[)(.*?)(?=\])/;

Old answer:

Solution:

var regex = /\[(.*?)\]/;
var strToMatch = "This is a test string [more or less]";
var matched = regex.exec(strToMatch);

It will return:

["[more or less]", "more or less"]

So, what you need is the second value. Use:

var matched = regex.exec(strToMatch)[1];

To return:

"more or less"

Answer 2

Most updated solution

If you are using Javascript, the best solution that I came up with is using match instead of exec method. Then, iterate matches and remove the delimiters with the result of the first group using $1

const text = "This is a test string [more or less], [more] and [less]";
const regex = /\[(.*?)\]/gi;
const resultMatchGroup = text.match(regex); // [ '[more or less]', '[more]', '[less]' ]
const desiredRes = resultMatchGroup.map(match => match.replace(regex, "$1"))
console.log("desiredRes", desiredRes); // [ 'more or less', 'more', 'less' ]

As you can see, this is useful for multiple delimiters in the text as well

Answer 3

If you need extract the text without the brackets, you can use bash awk

echo " [hola mundo] " | awk -F'[][]' '{print $2}'

result:

hola mundo

Answer 4

You just need to 'capture' the bit between the brackets.

\[(.*?)\]

To capture you put it inside parentheses. You do not say which language this is using. In Perl for example, you would access this using the $1 variable.

my $string ='This is the match [more or less]';
$string =~ /\[(.*?)\]/;
print "match:$1\n";

Other languages will have different mechanisms. C#, for example, uses the Match collection class, I believe.

Answer 5

This one specifically works for javascript's regular expression parser /[^[\]]+(?=])/g

just run this in the console

var regex = /[^[\]]+(?=])/g;
var str = "This is a test string [more or less]";
var match = regex.exec(str);
match;

Answer 6

PHP:

$string ='This is the match [more or less]';
preg_match('#\[(.*)\]#', $string, $match);
var_dump($match[1]);