If the algorithm depends on the order of function calls in the block, is that not good?

Question

Programming

If the algorithm depends on the order of function calls in the block, is that not good?
For example:

{
    SendABC();
    ShowWindow();
}

and

{
    ShowWindow();
    SendABC();
}

will give different end results.

Answer 1

it's pretty logical actually:
Backup()
Remove()
and
Remove()
Backup()
will give a slightly different result

Answer 2

The order of execution of operations within one function plays a role in 90% of cases. If we first do actions, and then initialize the values, then we should not be surprised at errors and constantly the same results. But there are exceptions. 1) I recommend minimizing the dependence on the order of execution of event handlers. It is not necessary to do 2 handlers for one event, and then pray that one will be executed first, and then the other. 2) Parallel execution of several tasks. Again - data initialization in one thread, processing in another .. The fact that you launched the first thread first cannot give a 100% guarantee that by the time the second thread is launched, the data will be initialized.

Answer 3

It's called Side Effect .
In imperative programming, when working with mutable structures / objects, nothing guarantees against side effect, that is, the order of calls can always matter (at least you should always expect this from someone else's code).
The opposite is "pure" computing, which guarantees no side effect. This is achieved:
- in imperative programming: by switching to using only immutable structures/objects.
- in declarative programming: many languages ​​are "clean" out of the box, this is their inherent property.