They had a router package in angular 2 which had 3 as it major version number. To sync all version numbers, they decided the next version would be 4. http://an

They had a router package in angular 2 which had 3 as it major version number. To sync all version numbers, they decided the next version would be 4. http://angularjs.blogspot.com/2016/12/ok-let-me-explain-its-going-to-be.html http://angularjs.blogspot.com/2016/12/ok-let-me-explain-its-...