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Welcome back. I hope you were able to solve the challenge.

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Let's go over it together, and I'll give you my solution to it.

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This is a pretty simple challenge,

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but it's important that you get it because we have to be able to compile, build,

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link and run.

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Obviously, we don't want any compiler errors, we don't want any compiler warnings.

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So let's start here.

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What I've done is I've created a challenge solution project based on the template.

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And here's my main cpp. It's just a simple Hello World.

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So this is the one I'm going to modify. All right.

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So let me change a little bit of this. I'm going to get rid of that statement right here,

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and we'll totally start from scratch. Now remember, we need to include

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the iostream library. This is how we do input and output.

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This is how we do our cins and our couts.

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So first thing I want to do is I want to prompt the user.

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I want to say std::cout,

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and there's my insertion operator. I'm just going to simply say enter

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your favorite number

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between,

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let's say, 100.

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And we'll put a colon there

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and a semicolon on the end. That will prompt the user.

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Okay. Now we want to be able to read that number from the user.

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Remember, when we read something,

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we need to store it somewhere. So we need to store that in a variable.

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In this case, it's going to be a whole number so we're going to use an integer. So I'm just going to say int

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favorite number, just like we did with that first program we wrote.

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So that's my favorite number, perfect.

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Now I can read into that variable, so I can say std

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from cin.

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I want to extract so I'm using the operator going the other way

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into favorite number.

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Okay. So at this point, I've prompted the user.

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They've typed in a number.

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I've read that number, and I've stored that number in

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this favorite number variable right here.

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The last thing to do is to print out those two statements. So first, I'm going to say

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cout,

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and I'll say "Amazing.

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That's my favorite number too."

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And we'll print a new line here so we can go to the next line.

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We'll say endl, followed by a semicolon.

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And this is the only difference now between this program and the one that we wrote previously.

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We want to be able to display the number. Say no really.

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Whatever you entered was or is my favorite number.

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So in this case, let's do that again. We'll do std,

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and we'll do again cout, and we're going to write to that stream,

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and I'll say "No really!"

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And I'll put a comma here followed by a space

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because we want this to be spaced out nicely.

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And I'll show you what the problems may be if you don't do that in a second.

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And at this point, we're going to insert our favorite number right in here.

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And we'll do another insertion operator.

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Remember, we can stream all these things together we can do as many as we want.

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And we'll say space is my favorite number.

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And we'll finish it off with a new line.

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Let's try that. We'll go up to build,

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run and build and execute.

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We've got a clean compile and it's running.

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Enter your favorite number between 1 and 100. Let's say it's 10.

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Amazing, that's my favorite number too.

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No really. 10 is my favorite number,

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perfect. That's exactly what we wanted to solve.

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Now the reason that I put in these little spaces here is because let's say I don't

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put that space in there and I don't put the space in here

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just like that. And let's run this again now. You can see that

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the output is not going to look right.

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So in this case let's say I typed in 25

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and you can see amazing that's my favorite number too, that's fine. But now look, no really

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comma 25. No space between 25 and the little I for

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and the lowercase I for is

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my favorite number. So you can see that the output doesn't really look very nice.

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So all we're doing is just formatting it.

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We'll talk more about writing to streams and using manipulators so that we can really get

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more fine grained control of what we want this to look like.

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But for now we, could just put spaces right in here.

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And we'll try that again. Build and run.

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My favorite number is 10.

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No really, 10 is my favorite number, perfect. So that's it.

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And that's that's the solution to this challenge.

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As I said it's a pretty simple challenge,

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but there's a lot of pieces here that come together.

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In the next few sections, we'll talk about the structure of the c++ program

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as well as variables. We'll talk a lot about variables

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how we declare them, how we define them, how we initialize them and how we use them

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but you got a taste of it here.