How to determine the Opera browser using JavaScript

Question

I want to determine that the browser of the client machines in Opera or not using JavaScript, how to do that?

Answer 1

The above answers no longer work in the new Opera 30. Since Opera now use Chromium. Please use the below:

var isChromium = window.chrome,
    isOpera = window.navigator.userAgent.indexOf("OPR") > -1 || window.navigator.userAgent.indexOf("Opera") > -1;
if(isChromium !== null && isOpera == true) {
   // is Opera (chromium)
} else { 
   // not Opera (chromium) 
}

The new Opera 30 release now fully uses Chromium and also changed their userAgent to OPR