Multiple Conditionals

Quick reference

• 00:04 In the last video, we looked at conditional statements,
• 00:07 in this video I want to look at multiple conditional statements using and and or.
• 00:11 So we already sort of have multiple conditional statements right here by using
• 00:16 this elif.
• 00:17 So this is our first conditional statement.
• 00:19 This is our second conditional statement.
• 00:21 So that's definitely multiple conditional statements.
• 00:23 But sometimes you want to run multiple conditional statements up at the top
• 00:28 before you even go down and evaluate anything else.
• 00:31 So you do that using these logical operators and and
• 00:35 or, lowercase, and and or.
• 00:37 So let's go ahead and get rid of this and let's just start over up here.
• 00:42 So to us and and or, you just type and and then pass in whatever else you want to do.
• 00:47 So let's say, num < 100.
• 00:50 So if we save this and run it, nothing happens.
• 00:54 Because num is 3, 3 is not greater than 5, and
• 00:57 even though our next statement, is 3 less than 100, yes, it is.
• 01:03 3 is definitely less than 100.
• 01:05 But for the logical operator and, both of these conditional statements have
• 01:10 to be true in order for this whole thing to evaluate true.
• 01:13 In which case, this will print out, otherwise the program just stops.
• 01:16 So we could change this, we could say, is num greater than 5?
• 01:20 We change it to 6.
• 01:22 Now this becomes true, is 6 less than 100?
• 01:24 Yes it is, so that becomes true.
• 01:26 And if we save this and run it, num is greater than 5, which is this.
• 01:31 So that's and.
• 01:33 You can use all of your comparison operators obviously, save this and run it.
• 01:37 It's no longer going to be true because 6 is not equal 100.
• 01:40 And you can mix and match any which way you want.
• 01:43 Now you can keep going, go and and and, and just keep slapping in more
• 01:46 conditional statements between the parentheses and it'll keep working.
• 01:50 Not quite sure why you would want to do that, but you can definitely do that.
• 01:53 So that's the logical operator and.
• 01:55 The next one is or.
• 01:57 So now if we save this and run it, we get, Num is greater than 5.
• 02:02 For or, only one of these has to be true.
• 02:06 They can both be true, but only one has to be true.
• 02:08 So in this case, 6 is indeed greater than 5.
• 02:12 6 is not equal to 100, so this one is false, but this one is true.
• 02:18 And like I said, with or, either one has to true for the whole thing to be true.
• 02:22 So that's sort of the difference between and and or.
• 02:25 So, let's do it again, is 5 greater than 5?
• 02:28 No, it's not.
• 02:29 Is 5 equal to a 100?
• 02:31 No, it's not.
• 02:31 If we save this and run it, nothing happens.
• 02:34 Because in this case, both of these are false, and so absolutely nothing happens.
• 02:38 So with or, one or the other has to be true.
• 02:41 And you can keep going, you don't have to use just two.
• 02:43 You can go or () or (), just like with the and, you can do as many as you want.
• 02:48 or (num == 1000), I don't know.
• 02:54 Doesn't work, right?
• 02:55 We if we change it to 6,
• 02:56 it does work because this is true even though this is false and this is false.
• 03:01 So no matter how many of them you have,
• 03:03 at least one of them has to be true in order for or to evaluate to true.
• 03:08 So lots of different circumstances, lots of different times you're going to want to
• 03:11 do this instead of using an elif statement.
• 03:14 And you'll see that as you move on and start to learn more about programming.
• 03:17 You'll see different times when you're going to be like, I should use and
• 03:21 there or an or there instead of an elif.
• 03:22 It'll make sense to you.
• 03:23 So those are multiple conditional statements.
• 03:25 In the next video, we're going to look at Python formatting.

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