Well == is a question or a query rather than a declaration of the state of things because it isn’t necessarily true.
You can write
a = (3 == 4)
which is perfectly valid code; it will just set a to be false, because the answer to the question “does 3 equal 4?” is no.
I think you’ve got it anyway.
Ok after reading the article this is bullshit. It’s only because they are counting JavaScript and Typescript separately.
They seem exactly the same to me: when a variable is assigned a value, it’s equal to that value now.
Yeah it’s confusing because in maths they are the same and use the same symbol but they are 100% not the same in programming, yet they confusingly used the same symbol. In fact they even used the mathematical equality symbol (=) for the thing that is least like equality (i.e. assignment).
To be fair not all languages made that mistake. There are a fair few where assignment is like
x := 20
Or
x <- 20
which is probably the most logical option because it really conveys the “store 20 in x” meaning.
Anyway on to your actual question… They definitely aren’t the same in programming. Probably the simplest way to think of it is that assignment is a command: make these things equal! and equality is a question: are these things equal?
So for example equality will never mutate it’s arguments. x == y will never change x or y because you’re just asking “are they equal?”. The value of that equality expression is a bool (true or false) so you can do something like:
a = (x == y)
x == y asks if they are equal and becomes a bool with the answer, and then the = stores that answer inside a.
In contrast = always mutates something. You can do this:
a = 3
a = 4
print(a)
And it will print 4. If you do this:
a = 3
a == 4
print(a)
It will (if the language doesn’t complain at you for this mistake) print 3 because the == doesn’t actually change a.
= and <= match the mathematical operators. The question you want to ask is why doesn’t it use = for equality, and the answer is that = is already used for assignment (inherited from C among other languages).
In theory a language could use = for assignment and equality but it might be a bit confusing and error prone. Maybe not though. Someone try it and report back.
It’s not too bad if you strictly enforce Pyright, Pylint and Black.
But I have yet to work with Python code other than my own that does that. So in practice you are right.