Errata for Pragmatic Guide to JavaScript

#49514: One of the reported errata is itself possibly incorrect. There reported errata in question is:

"#46276: JavaScript code in 'Try this example: "privates properties.", var publicField = 'foobar'; should be publicField = 'foobar'; --Klaus Rohe"

The code in the book is correct. Either version (that in the book or that suggested by Klaus) will work. I verified this in a JavaScript console myself.

However, the book's version exports "publicField" by making it a property on the object returned from the anonymous function. The version suggested in the errata report, that of removing the "var" before the definition of the "publicField" variable is unnecessary. In fact, the only effect it has is to make said variable global (in the context in which you run said example). This actually breaks the spirit and intent of the code example and of what the section of the book it trying to demonstrate: keeping your own junk out of the global namespace.

Here's my console session log (executed in the Chrome Browser's JavaScript Console):

> var obj1 = (function() { var privateField = 42; var publicField = 'foobar'; function processInternals() { alert('Internal stuff: ' + privateField); } ; function run() { processInternals(); alert('Still private stuff: ' + privateField); alert('Public stuff: ' + publicField); } ; return { publicField: publicField, run: run }; })();
=> undefined
> var obj2 = (function() { var privateField = 43; publicField = 'foobar2'; function processInternals() { alert('Internal stuff: ' + privateField); } ; function run() { processInternals(); alert('Still private stuff: ' + privateField); alert('Public stuff: ' + publicField); } ; return { publicField: publicField, run: run }; })();
=> undefined
> obj1.run()
=> undefined
> obj1.publicField
=> "foobar"
> obj1.processInternals()
=> TypeError: Object #<Object> has no method 'processInternals'
> obj1.privateField
=> undefined
> obj2.run()
=> undefined
> obj2.publicField
=> "foobar2"
> obj2.processInternals()
=> TypeError: Object #<Object> has no method 'processInternals'
> obj2.privateField
=> undefined
> publicField
=> "foobar2"--Kendall Gifford

#45939: I was hoping the Guide (or at least the Cheat Sheet) would include a reminder of JavaScript's odd way of defining a new class. Perhaps in a future update?--Sven Aas

#45835: "jQuery is, at the time of this writing, at version 1.4.2."

This was already mentioned at the bottom of the previous page:
"(The current version at the time of this writing is 1.4.2.)"

It seems a bit redundant to state this fact less than 1 page later.

Also, the current release is 1.4.4.--Eric Litwin