Keen eyes

[BartC]

On 17/01/2016 08:25, Chris Angelico wrote:
> On Sun, Jan 17, 2016 at 6:37 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> Technically it defaults to non local. The var statement allocates a
>> variable within the current scope. Otherwise it searches up the chain of
>> parent scopes for a matching variable...
>
> This far, it's exactly the same as C.
>
>> ... terminating at the global scope.
>
> This is the bit that gets ridiculous. Undeclared variables in C are
> compile-time errors. Undeclared variables in JS are implicit globals.
> This is stupid.

My own language is something in-between. If a name is not declared 
locally, it will look at more global scopes. If nothing is found, it 
will auto-declare a local.

So the JS bug wouldn't occur. However, there is the problem that, given 
a perfectly working function with implicitly locals, at some point in 
the future someone could introduce a global that will clash with the 
name of a local, and screw things up.

Because of that, the Python scheme is better on the whole. The only 
issue is that sometimes you think you're assigning to a global, but it's 
really a local if you forget the 'global' declaration within the function.

-- 
Bartc