Logic: If/Else Or Operators

Quick reference

• 00:04 Okay, in the last video, we looked at multiple comparisons,
• 00:07 multiple conditionals using and.
• 00:08 In this video, we want to look at multiple conditionals, multiple comparisons, and
• 00:13 I use those two phrases sort of interchangeably using or.
• 00:16 So, in the last video and, the whole thing was all of these have to be true
• 00:21 in order for the entire thing to evaluate true, that's how and works.
• 00:26 Or is different, it's or, so one or
• 00:29 the other has to evaluate to true in order for the entire thing to be true.
• 00:34 So, let's just play around this here.
• 00:36 So, let's say,
• 00:40 if (a > b | | a < 1,000).
• 00:48 Then we want to do this.
• 00:50 And this is the or operator these two, sort of, we call them pipes in
• 00:54 programming languages, is just the straight upright bar.
• 00:58 You have to hunt around in your keyboard, all keyboards are different.
• 01:01 You might have to hunt around on your keyboard in order to find it.
• 01:04 Mine is in sort of the top right corner above the Enter key.
• 01:07 Hit Shift and the pipe thing twice.
• 01:10 I don't know exactly where it's going to be on your keyboard, but
• 01:13 it's these upright straight bars, and it's two of them, right?
• 01:16 So, if 200 is greater than 19 or
• 01:20 200 is greater than 1,000.
• 01:24 Now this clearly is not true, but this is, and
• 01:28 like I said, one or the other has to be true.
• 01:32 So, this should evaluate to true, and then print this thing out onto the screen.
• 01:36 So, go ahead and save this and run it.
• 01:40 Sure enough, yep, 200 is greater than 19.
• 01:43 Or what if both of these are false?
• 01:45 Let's say, if a is less than b, it's clearly not.
• 01:49 Or a is greater than 1,000, it's also clearly not.
• 01:53 So, neither of these are true.
• 01:55 What do we think's going to happen?
• 01:57 Well, it's probably going to evaluate to false, if neither of them are true, and
• 02:01 sure enough you get nothing here, because neither of them are true.
• 02:05 So, that's all, and just like with and, you can have this on multiple lines.
• 02:10 So, you could do something like this, if you wanted to, to make it easier to read,
• 02:15 totally up to you just a matter of style.
• 02:17 And just like with and, you can do as many of these as you want.
• 02:20 So, you can just keep stringing them along, and doing more or,
• 02:24 or, ors, and that works, too.
• 02:25 So, we can say if a == b, which clearly is not, we run this,
• 02:30 it's still going to evaluate to false.
• 02:33 Sure enough, nothing there and pretty cool.
• 02:36 So, there are times when you might and, and
• 02:39 there are times when you might need or.
• 02:41 There are plenty of times when you don't have to use either of these and you just
• 02:45 want to make one comparison, you can use just your basic FL statement for that.
• 02:48 It's really just up to you in what you need to do in your program, but
• 02:51 these tools are so important.
• 02:52 Like I said, a couple of videos ago, if FL statements logic is just so
• 02:56 important in computer programming and and, or just make it even more powerful.
• 03:00 Now some people forget these, and in some programming languages you can just use or
• 03:07 like that, if we save this and run it, we get an error.
• 03:11 You can't do that in C-Sharp.
• 03:13 Same thing with and,
• 03:14 some programming languages just allow you to use the words and.
• 03:18 So again, it's C-Sharp, we can't do that, we get errors as well.
• 03:22 So, just realize you have to use either the double ampersand or
• 03:27 the double bars for and and or.
• 03:30 And you may have to Google it every once in a while, because you can't remember,
• 03:32 wait, what was or again?
• 03:34 But that's what it is, and that's all there is to it.
• 03:37 So, that's all for and and or.
• 03:38 In the next video, we'll look at as if statements.

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