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Matthew Ison5,989 Points
Delete __iadd__ and everything worked the same...
In this video it appears to be showing that iadd let's us store the numerical value in age(age += 1) and then add it to another number. However, I deleted the iadd function and age+=1, then age +5 gave the same output as when the iadd was in place.
So if it wasn't necessary for the example in the video, then what is an example where it's actually necessary?
Jeff MudayTreehouse Moderator 28,715 Points
This can be a little confusing at first.
__iadd__ is the "inplace addition" operator. It is different than the
__add__ method which simply returns the RESULT of the addition to another object. But instead the
__iadd__ is 2 operations with one operator... it evaluates first then and replaces itself with a new object.
Since the addition is "inplace" it means that the value of object is modified in place. Its counterparts are
iconcat for strings.
x = 3
# the iadd adds and modifies the object, 2 operations in one!
x += 1