Assignment Operators

Quick reference

• 00:04 In this video, I want to look at assignment operators.
• 00:07 And we've kind already seen some assignment operators in action.
• 00:10 We had our variable first_name = John.
• 00:15 Right here, you were using an assignment operator, and
• 00:17 you probably didn't even know it.
• 00:18 It's the single = sign right here, is an assignment operator.
• 00:22 It's assigning the string John, into the variable first name.
• 00:26 So we're assigning it in.
• 00:29 And that's what that single = does.
• 00:31 So, any time you're using a list, a variable, a tuple,
• 00:35 a dictionary, number and you use this single = sign, you're signing.
• 00:39 Well that's pretty basic, pretty simple, you don't even really need to think of
• 00:42 this as an assignment operator, it's just blindingly obvious, right?
• 00:46 Well, that's true, and there are also some other assignment operators, and
• 00:49 those are what I would really want to focus on in this video.
• 00:51 What are the other assignment operators?
• 00:53 Well, a couple of videos ago, we looked at math operators.
• 00:55 And all of those math operators can be turned into assignment operators,
• 00:59 and you do that just by slapping an = sign next to them.
• 01:02 So you have +=, -=, *=,
• 01:06 /=, **= and %=, one equal to sign.
• 01:13 And so, these are all now assignment operators.
• 01:16 And what they're doing is adding and assigning, subtracting and assigning,
• 01:21 multiplying and assigning, and on, and on.
• 01:23 So, what does that mean?
• 01:24 Well, let's create a variable, and let's just call it num.
• 01:27 And I'm going to say, num = 41.
• 01:29 And we can print this out, you know how to do this, and it's just 41.
• 01:33 But what if we wanted to add 1 to our num?
• 01:37 Normally, you would just go, num = num + 1,
• 01:41 if we do this and run it we get 42.
• 01:44 because we're taking our num which is 41, we're adding 1 to it which is 42,
• 01:49 and we're taking that and assigning it back in to the variable num.
• 01:53 So from now on from line 9 down, anytime we print out num it's going to be 42.
• 01:58 Well, that's fine, you can do that, it's much easier just to go num +=1.
• 02:04 And if we save this and run it, we're going to get the same 42.
• 02:07 So, what would doing is adding in assigning, or subtracting and assigning.
• 02:12 And that's important because say we get rid of this, and
• 02:15 we just come down to our print statement and we go num + 1.
• 02:18 Well, if we save this and print it, we're still going to get 42.
• 02:21 But then if we come down below it and go num again,
• 02:25 the first time it's going to print 42.
• 02:28 The second time it's going to print 41.
• 02:30 Because right here, all we did was add,
• 02:32 we didn't then assign that back in to the variable.
• 02:35 So from here down, our num is still going to be 41,
• 02:38 even though we added 1 to it right here.
• 02:41 So, because of that, it's super useful to use this num += 1
• 02:46 assignment operator, or you could do subtraction as well.
• 02:52 Print this out 40, you do multiplication like said, all those math operators,
• 02:56 you can turn into assignment operators.
• 02:58 Let's change this to 2.
• 02:59 So 41 times 2 is going to be 82, and divide, and go through all of them.
• 03:03 So, super useful.
• 03:05 And you might be thinking well okay, that's fine, but
• 03:09 why don't we just go num = num + 1, instead of going
• 03:15 += 1.
• 03:16 Well you could do this, these two lines line 9 and 11, they end
• 03:20 up being the exact same thing, but this line here is just, it's easier to do.
• 03:24 It's much less stuff to write, and computer programmers coders.
• 03:28 We are notoriously lazy.
• 03:30 We hate typing stuff.
• 03:31 We hate writing things.
• 03:32 Anytime I can write less stuff, I'm going to do that.
• 03:35 And it makes the code easier to read more elegant.
• 03:38 We like elegance in programming and all that good stuff.
• 03:41 So, those are assignment operators, super useful.
• 03:43 You're going to use them all the time.
• 03:45 I mean, just think about it.
• 03:46 Like, if you have a shopping cart online and you're selling things,
• 03:49 if somebody wants to add a new item to their shopping cart,
• 03:51 you're going to want to increment they're running total.
• 03:54 You're going to use an assignment operator, to += that new total.
• 03:57 And just a zillion other things you can use this for.
• 03:59 So, super useful, super easy.
• 04:01 Those are assignment operators.
• 04:03 In the next video, we're going to look at lists.

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