Regular expression to match single bracket pairs but not double bracket pairs

Question

Is it possible to make a regular expression to match everything within single brackets but ignore double brackets, so for example in:

{foo} {bar} {{baz}}
         


        

Answer 1

To only match foo and bar without the surrounding braces, you can use

(?<=(?

if your language supports lookbehind assertions.

Explanation:

(?<=      # Assert that the following can be matched before the current position
 (?

EDIT: In JavaScript, you don't have lookbehind. In this case you need to use something like this:

var myregexp = /(?:^|[^{])\{([^{}]*)(?=\}(?!\}))/g;
var match = myregexp.exec(subject);
while (match != null) {
    for (var i = 0; i < match.length; i++) {
        // matched text: match[1]
    }
    match = myregexp.exec(subject);
}