Swapping is one of the foundational operations you find in algorithms.
Now, generally speaking, when we're swapping two simple values,
an a and b, it's a fixed amount of computing cost.
We tend to have a temporary, we assign to the temporary, the value of
the first object, then we re-assign the first object value from the second object.
So the temporary is holding the original value, and
now we use the original value and assign it to the second object.
So that's why we need the temporary.
We can't just, we can't instantly interchange the two objects.
We could if we were like in the old Genie movies or
Genie TV series, you can snap your fingers and they both jump into the other box.
That doesn't happen.
In the real world, in the C world, you need this intermediary.
So first, copy it, place it safely here,
now do the interchange, from one now take the copied thing and do the interchange,
and that's a fixed set of operations on a simple data type like an int.