Why people dislike global variables so much while I find them so convenient?
acehreli at yahoo.com
Tue Jan 25 15:47:12 UTC 2022
On 1/25/22 01:53, rempas wrote:
> people dislike global variables
The situation is much better in D because I suspect what you call global
is D's module-scope and thread-local.
(Note: I don't want to argue whether thread-local by default was a good
decision or not but I certainly take full advantage of the ease of
thread-local variables in D.)
So, module-scope variables are just fine: std.parallelism uses a default
ThreadPool object, std.stdio functions use stdout, in this case a truly
global object, etc.
> When I have a variable that I must pass down to 5-6
> functions, I find it much easier to make it global rather than having it
> been passed in all the functions that need it.
I've used that method once, which I mentioned at this point during a
Both you and I realize that a module is an object and in our case there
is a single object of it. That works.
When you need more than one object (more than one context), then you
move all those variables to a user-defined type and they become proper
> global variables can mess me up
Otherwise, as everybody else told, global variables can be very dangerous:
That report mentions "thousands of global variables", all of which I bet
started as "what can go wrong?"
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