The built-in cross-browser handling saves oodles of time in development too. jQuery is one language where it is necessary to keep closely in touch with it’s developments to ensure that your code works correctly with new releases plus also takes advantage of any new selectors which are added in as it develops onwards.
The up-take of jQuery amongst front-end web developers has been huge and this has ensured that support and discussion in it’s use is considerable, making it far easier to solve bugs and problems as they arise during development. This is another crucial factor in determining which framework to use.
As a contractor in London, i have found that many companies now use jQuery as a way of producing development tasks quickly, with reduced bugs across different browsers and devices. jQuery Mobile has also now arrived, with specific devotion to mobile devices, but the original is still my preferred route. Bootstrap can then be used alongside it to provide similar consistency across smaller devices.
One constant problem that i have encountered with jQuery is that when updating to newer versions there are always several issues which need fixing, such as deprecated features which were previously fine. Experience helps here to almost be able to predict what issues will crop up from moving between versions, and there are also migration scripts as a fallback if necessary.
jQuery’s noconflict mode can be used where you have different items which require different versions of the framework, but personally i will always try to avoid this scenario where ever possible by ensuring that everything functions correctly on the latest version that you are using.