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So in this video we're going to do a code along and it's going to illustrate one other way to use a

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while loop.

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So so far we've been using a while loop where we use numbers and we have a range.

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So we print numbers from 10 to 50 and that is a set range.

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So there's another way to use a while loop where we don't actually know exactly how many times it will

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run it's not pre-determined.

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So this annoy o matic that we're going to make it.

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It's a fancy term for an annoying Web site that constantly asks you Are We There Yet.

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Until you enter the word yes or yeah.

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Anything else to ask you Are we there yet again.

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So let me show you I'll refresh the page.

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Are we there yet.

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Let's say no.

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Are we there yet.

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Not yet.

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Are we there yet.

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And now let's say Yes.

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And it tells us yes we finally made it.

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So that's what we're going to make to start.

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So to get going.

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We need to have a file with our HMO.

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And I just called mine and noid HMO and then we're going to add in our scripts tag

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and then we'll need to make the file.

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So let's call this annoyed.

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Yes let's make our new file a noise.

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J.S. in the same directory and I always like to add my alert connected just to make sure.

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Now let's open up our version and we won't see anything on the page but it should say connected.

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All right.

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So the first thing that we want to do is just ask a user are we there yet.

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So we'll make it a variable called the answer equal to prompt.

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Are we there yet.

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Save that.

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So then the next step is to check did the user say yes.

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So we could use an if statement like this if answer equals equals yes then we'll do an alert.

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Yay we made it and that's great and we could have an else where we then ask again and you don't have

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to do this part.

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But I'm just illustrating to you without a while loop we could do this but it will only run one time

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so it will ask are we there yet.

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And if I enter no then it will run the else.

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Var answer equals are we there yet again.

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And then nothing else happens.

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So I'll show you that refresh are we there yet.

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No.

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Are we there yet.

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No and that's it.

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So rather than using just a simple conditional we're going to use a while loop but it's going to use

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a lot of the same code that we have here.

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So we just write while answer is not equal to yes.

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So while the user has not said yes we're going to prompt them again.

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And that's all there is to it.

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So while the answer is not equal to the word yes let's ask them again.

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Are we there yet.

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And then finally at the very end we can just have an alert that says hey we made it and this won't run

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Intel this loop is over.

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And so that means that the user has to have typed in yes in order to get this far.

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So let's try it out go back to the browser are we there yet.

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No.

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Nope.

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No.

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No.

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Anything we want.

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And then as soon as we type the word yes it tells us yea we made.

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So I wanted to do this to show you that you can use a while loop in another way.

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So this is not a pre-determined loop that runs 10 times or five times.

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It can vary and it's all up to user input.

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So there was one more requirement which is that we could also type the word Yeah.

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Why E.H. instead of yes.

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And either one would work.

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So that's pretty easy to implement.

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All we need to do is add in a another part of this conditional where we want to add an and well answer

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is not equal to yes.

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And answer is not equal to.

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Yeah.

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Then we'll ask again.

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And that's it.

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So refresh types of thing it keeps asking then I could enter.

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Yeah.

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And it says We made it and I can also do that entering Yes.

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So there's a version 2 here that's just a little bit more advanced where you don't have to enter the

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exact word.

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Yes or yeah only you could enter any phrase as long as has.

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Yes or yeah in it.

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So I'll show you.

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It could be something like.

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Yes we are which currently doesn't work in our other version because it's checking to see if the entire

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string is yes or yeah.

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So what we want to do is check if the string contains Yes if part of it matches yes but not all of it

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necessarily.

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So to do that there's a method we can use called index of.

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So I'll show you an example in the con..

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If I make a string called Hello world and I use index of.

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So as Tiare index of in in parentheses I give it a string like w.

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It's going to give me the number where w occurs which is 6 0 1 2 3 4 5 6.

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But I can also use it on a full word like world and it tells me that world occurs starting at index

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6 and if I try and do something that doesn't exist.

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So in our case let's try Yes that's not in Hello world.

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It gives me negative 1 so I can use that to my advantage.

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So I want to check is yes anywhere in the input string anywhere an answer.

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So to do that and it go back down here and for our version to I'm just going to keep our initial code

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and commented out and then all right version 2.

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And put this down here.

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So this is going to stay the same.

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This is going to be different.

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So we're going to want something like answer that index of.

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Yes.

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And we want to see is it equal to negative 1.

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So that means that the word yes does not exist inside of our answer.

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So let's try that out.

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Refresh are we there yet.

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No.

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Are we there yet.

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No.

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Are we there yet.

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Yes I think so.

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And it says yeah we made it.

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Try it again and let's try.

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We are there.

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Yes.

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And it tells us we made it.

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OK.

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So that's version 2 and that's all we needed to do there.

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So that's all there is to version 2.

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I just want to show that you can use index of to make your input checking a little bit more flexible