Comparison Operators

Quick reference

• 00:04 In this video, I want to talk about comparison operators.
• 00:07 And comparing different things is super important whenever you're doing any sort
• 00:11 of computer programming, you're always going to want to compare things.
• 00:14 And in the next video, we're going to look in conditional statements.
• 00:17 They allow us to take our comparisons and do different things with them.
• 00:21 But before we do that, we have to learn about the actual comparison operators,
• 00:24 the little symbols that we use to compare two things.
• 00:26 So these are super simple, and the first one is double equal to sign.
• 00:30 So remember, we've looked at this many times.
• 00:33 Let's go first_name = "John".
• 00:37 So this is a single equal to sign and it's an assignment operator.
• 00:41 It is assigning the value of John and the first name.
• 00:44 This is a double equal to sign and it's not assigning, it's asking a question.
• 00:49 It's saying, is this equal?
• 00:50 So, to use this, we might say let's use a number.
• 00:53 Let's go 10 == 10, right?
• 00:56 This is a true statement.
• 00:58 So let's just get rid of this.
• 00:59 So in fact, if we print this out, what we're asking here.
• 01:04 We're asking Python, Python is asking is 10 == 10?
• 01:08 And that's using those two equal to sign.
• 01:10 So if we save this and run it, we're going to get back true.
• 01:13 So true, 10 does equal 10 and true and false or what's called Booleans.
• 01:18 And just a fancy word for true or false and a Boolean is actually a data type.
• 01:21 We didn't talk about it because it's just true or false, that's all there is to it.
• 01:24 But we can change this around, we can say 9, is 9 == 10.
• 01:29 If we save this and run it, we're going to get false because 9 and
• 01:32 10 are not equal obviously.
• 01:33 So that's the first one, first comparison operator.
• 01:36 And let's just make a quick list here, equal to.
• 01:39 The next one is not equal to, and we'll just use this exclamation point equal to.
• 01:45 And in most programming languages, exclamation marks mean not.
• 01:48 So this is saying, is this not equal to?
• 01:51 Is 9 != to 10?
• 01:53 And it is true that 9 and 10 are not equal.
• 01:56 So we should get true, or we could change this to 10.
• 02:00 In which case, it will be false because it's asking, is 10 not equal to 10?
• 02:05 Well, no, 10 and 10 are equal.
• 02:06 So this is false.
• 02:07 It's false that they are not equal, right?
• 02:10 So, those are the two big ones, right?
• 02:12 The rest you're going to be familiar from basic math as a child, and
• 02:17 I'm just going to write them down here.
• 02:18 Greater than equal to and less than or equal to.
• 02:22 So, greater than, is 10 greater than 10?
• 02:25 That can be false because no, 10 is not greater than 10.
• 02:28 Is 11 greater than 10?
• 02:31 True, right.
• 02:31 So same thing with the less than sign.
• 02:34 Just asking question, is 11 less than 10?
• 02:37 Nope. Is 1 less than 10?
• 02:41 True, right?
• 02:42 So finally, there's these greater than or equal to.
• 02:45 Is 1 greater than or equal to 10?
• 02:48 Absolutely not, is 10 greater than or equal to 10?
• 02:52 And in this case, one or the other have to be true or they can both be true.
• 02:56 So 10 is equal to 10.
• 02:58 So this should spit out true and we get true.
• 03:02 We change this to 11.
• 03:03 11 is greater than, it's not equal to.
• 03:05 11 is not an equal to 10 but it is greater than.
• 03:08 So, this will give us true.
• 03:10 Same thing for less than, less than or equal to.
• 03:12 Is 11 less than or equal to 10?
• 03:15 Nope, so we get false.
• 03:17 Is 10 less than or equal to 10?
• 03:19 Well it is equal to, so we get true.
• 03:21 Finally, is 9 less than or equal to 10?
• 03:25 Yes, it is less than so we get true.
• 03:27 So, those are our comparison operators.
• 03:29 They're very, very simple and we didn't do a whole lot in this video,
• 03:33 we just saw a bunch of trues and falses.
• 03:35 In the next video, we're going to look at conditional statements that will allow us
• 03:39 to use these things and then take certain action.
• 03:42 If it's true, do this.
• 03:44 Otherwise, do that.
• 03:45 Those are called if else statements.
• 03:47 Those are comparison operators.
• 03:48 In the next video, like I said, we'll look at conditional statements.

Lesson notes are only available for subscribers.