Regex to get string between curly braces

Try

/{(.*?)}/

That means, match any character between { and }, but don't be greedy - match the shortest string which ends with } (the ? stops * being greedy). The parentheses let you extract the matched portion.

Another way would be

/{([^}]*)}/

This matches any character except a } char (another way of not being greedy)

/\{([^}]+)\}/

/        - delimiter
\{       - opening literal brace escaped because it is a special character used for quantifiers eg {2,3}
(        - start capturing
[^}]     - character class consisting of
    ^    - not
    }    - a closing brace (no escaping necessary because special characters in a character class are different)
+        - one or more of the character class
)        - end capturing
\}       - the closing literal brace
/        - delimiter

If your string will always be of that format, a regex is overkill:

>>> var g='{getThis}';
>>> g.substring(1,g.length-1)
"getThis"

substring(1 means to start one character in (just past the first {) and ,g.length-1) means to take characters until (but not including) the character at the string length minus one. This works because the position is zero-based, i.e. g.length-1 is the last position.

For readers other than the original poster: If it has to be a regex, use /{([^}]*)}/ if you want to allow empty strings, or /{([^}]+)}/ if you want to only match when there is at least one character between the curly braces. Breakdown:

• /: start the regex pattern
  • {: a literal curly brace
    • (: start capturing
      • [: start defining a class of characters to capture
        • ^}: "anything other than }"
      • ]: OK, that's our whole class definition
      • *: any number of characters matching that class we just defined
    • ): done capturing
  • }: a literal curly brace must immediately follow what we captured
• /: end the regex pattern

Try this

let path = "/{id}/{name}/{age}";
const paramsPattern = /[^{\}]+(?=})/g;
let extractParams = path.match(paramsPattern);
console.log("extractParams", extractParams) // prints all the names between {} = ["id", "name", "age"]

This one works in Textmate and it matches everything in a CSS file between the curly brackets.

\{(\s*?.*?)*?\}

selector {. . matches here including white space. . .}

If you want to further be able to return the content, then wrap it all in one more set of parentheses like so:

\{((\s*?.*?)*?)\}

and you can access the contents via $1.

This also works for functions, but I haven't tested it with nested curly brackets.

This one matches everything even if it finds multiple closing curly braces in the middle:

\{([\s\S]*)\}

Example:

{
  "foo": {
    "bar": 1,
    "baz": 1,
  }
}

You can use this regex recursion to match everythin between, even another {} (like a JSON text) :

\{([^()]|())*\}

Even this helps me while trying to solve someone's problem,

Split the contents inside curly braces ({}) having a pattern like, {'day': 1, 'count': 100}.

For example:

#include <iostream> 
#include <regex> 
#include<string> 
using namespace std; 

int main() 
{ 
    //string to be searched
    string s = "{'day': 1, 'count': 100}, {'day': 2, 'count': 100}";

    // regex expression for pattern to be searched 
    regex e ("\\{[a-z':, 0-9]+\\}");
    regex_token_iterator<string::iterator> rend;

    regex_token_iterator<string::iterator> a ( s.begin(), s.end(), e );
    while (a!=rend) cout << " [" << *a++ << "]";
    cout << endl;

    return 0; 
}

Output:

[{'day': 1, 'count': 100}] [{'day': 2, 'count': 100}]

Your can use String.slice() method.

let str = "{something}";
str = str.slice(1,-1) // something