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Comment by mattmanser | Hacker News Reader

That's definitely not in javascript the good parts. It's a new thing and its spreading like some sort of horrible virus. It has quite the opposite effect that you're prescribing to it.

Your second link describes both variable hoisting, a real problem which causes serious problems, and function hoisting that has never been a problem as almost every other modern language behaves that way.

You don't seem to be a polyglot or you'd understand the problem immediately. Variable hoisting is just downright bizarre if you've worked in almost any other language, whereas function declarations can be anywhere in most languages and so when they are declared is almost completely irrelevant to a programmer.

Artificially assigning them to a variable so that suddenly function declaration order does matter is just downright weird. The 'normal' function declaration is better and clearer.

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I'm probably not the best person to have a debate about this since I don't have a traditional CS background. I dabble in many different languages, but I'll never claim to be an expert in any.

To your point about this not being in the book JavaScript the Good Parts, I re-downloaded my purchase from Oreilly to double check, and throughout the book, all functions are declared as variables. Here's a screenshot from the second page of the "Functions" chapter, which is the first time a function declaration is introduced in the book: https://dl.dropbox.com/u/1517499/Screen%20Shot%202013-03-26%...

Edit: Just an edit to add that I quickly perused the pdf and couldn't pick out anywhere where he explained why he recommends this way. In any case, I'm always open to any arguments one way or the other.

I don't think that's what he's addressing, though.

It's this:

var foo = function() { redeclaration(); }

that I believe he's referring to, unless I'm mistaken.

I don't believe so. It sounds like he prefers using function declations to function expressions. And this is incorrect according to most js gurus. For example:

http://javascriptweblog.wordpress.com/2010/07/06/function-de...

From that link:

"b) Function Expressions are more versatile. A Function Declaration can only exist as a “statement” in isolation. All it can do is create an object variable parented by its current scope. In contrast a Function Expression (by definition) is part of a larger construct. If you want to create an anonymous function or assign a function to a prototype or as a property of some other object you need a Function Expression. Whenever you create a new function using a high order application such as curry or compose you are using a Function Expression. Function Expressions and Functional Programming are inseparable."

Also this link: http://kangax.github.com/nfe/

brings up these disadvantages to function declarations:

* can't conditionally declare functions with consistent results across browsers * function declarations cannot appear in blocks (technically), though many implementations allow this in practice

finally, i'd argue that function expressions encourage you to think of functions as the first class objects js intended them to be

He included far more code than was necessary, if that's the case. I don't see why the implementation of the function expression would be relevant if so. Clarity would help here.

You're quite right. Bizarre that it didn't even register. At least that explains why some people have picked up that habit.

Crockford himself seems to have abandoned the habit if you check his github code.

Why would you want a function called "callback" polluting you global namespace?

What you suggest makes no sense in Javascript. Variable functions allow the developer to simulate namespacing in JS without polluting the global namespace.

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