In older browsers you still need a workaround. Start by trying to identify why you want to do it. The problem is that positive lookbehind feature may not be supported in all browser and we have to support IE 11. Ils vérifient une expression régulière (vers la droite ou la gauche de la position actuelle – basée sur l’avant ou l’arrière), réussissent ou échouent lorsqu’une correspondance est trouvée (en fonction de la position positive ou négative) et rejette la partie correspondante. B [/B] is supposed to match -- but not capture -- the match. All you can do is working with groups. But as the name is not the only information in a user agent string that is in that format, you can not discover the name of the browser, you can only check if the name you are looking for. For a tutorial about Regular Expressions, read our JavaScript RegExp Tutorial. Waldemar may recall more, I'd handed him the JS keys inside netscape.com to go do mozilla.org. The agent might be an older version of Chrome, from before support was added, or (because the feature was experimental at the time) it could be a later version of Chrome that removed it. Pull requests 37. In conclusion, if you take advantage of all of the above approaches, regex lookbehind syntax can be mimicked in JavaScript in the vast majority of cases. They only assert The syntax is: Positive lookbehind: (?<=Y)X, matches X, but only if there’s Y before it. When people say they want "browser detection", often they actually want "rendering engine detection". Tìm kiếm các công việc liên quan đến Javascript regex lookbehind support hoặc thuê người trên thị trường việc làm freelance lớn nhất thế giới với hơn 19 triệu công việc. That's unfortunate, but I'm not content with just resigning to that fact. Recommend downloading latest version of Firefox/Chrome/Edge) The (?