Most books on JavaScript either compare it to the better known class based languages such as Java or C++ and even go on to show you how to make it look like the one of these.
Just JavaScript is an experiment in telling JavaScript's story "just as it is" without trying to apologise for its lack of class or some other feature. The broad features of the story are very clear but some of the small details may need working out along the way - hence the use of the term "experiment". Read on, but don't assume that you are just reading an account of Java, C++ or C# translated to JavaScript - you need to think about things in a new way.
Just JavaScript is a radical look at the language without apologies.
JavaScript should not be judged as if it was a poor version of the other popular languages - it isn't a Java or a C++ clone. It does things its own way and sometime it can do unexpectedly clever thing [ ... ]
Working with lower-level data is very much part of graphics. This extract from Ian Elliot's book on JavaScript Graphics looks at how to use typed arrays to access graphic data.