Whilst updating nodejs and npm on a Centos 6 or 7 server running Apache, I hit a few walls and as a matter of process found some commands that are handy to run before doing a deep dive in Google.   Cleaning the cache sudo yum clean all rm -rf /var/cache/yum/* To make the cache sudo yum clean all; sudo yum makecacheIf you want to run several commands use semi-colon as noted above.   Updating When running an update command run sudo yum -y...

I had the issue where I needed to filter an array list by a specific column.  In my instance, the column is language.  To be able to reduce the query to the language column the code required is levels = selectedCategory?.levels.filter("language = %@", language)Language can be any string, in this instance for me language is a two alpha character such as 'fr', 'en' or 'de'. Further to this you can continue to chain this query through including sort as per levels =...