Re: setq and setq-default

["jronald" <followait@163.com>]

I think setq-default set a global variable, and setq set a variable in its 
scope, which may override the global one.
If so, can setq set a global variable when it is in the global scope.

If tab-width and default-tab-width both exsists, what is the priority emacs 
treats them?

<robert.thorpe@antenova.com> 
??????:1158164996.335560.182180@i3g2000cwc.googlegroups.com...
> jronald wrote:
>> I studied them for a while, but without details and examples.
>>
>> For example, what is the difference of the two below:
>> (setq-default tab-width 8)
>
> This is the general way to set the default value of a variable.  If you
> put (setq-default foo 9) then in the context of every buffer you create
> foo will be 9 unless the buffer has it's own value for that variable.
>
>> (setq default-tab-width 8)
>
> This means the same thing, except it is a mechanism specific to
> tab-width, not all variables have a special "default" form associated
> with them.  Only a handful have them, I don't know why, perhaps
> setq-default didn't exist in very early Emacs.
>