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An exercise challenge to create a function that takes in two parameters to find out if one is divisible by the other.
Challenge
Write a function that determines if a number is divisible by another. It will do the following:
 Accepts two Int parameters
 Figures out if the first parameter is divisible by the second
 Returns a Bool optional
 If the number is divisible it return a true else it returns a nil
 Call the function with 2 numbers and then print out whether “Divisible” or “Not Divisible”

0:01
As usual, we've covered a lot of ground in this course.

0:04
To reinforce all these new concepts, let's put them to good use.

0:09
Here's a challenge for

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you, write a function to determine if a number is divisible by another.

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It will do the following, accept two Int parameters.

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Figures out if the first parameter is the divisible by the second,

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returns a Bool as an optional, if the number is indeed divisible it

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returns a true, else it returns a nil.

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Finally, call the function with the two parameters.

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And then print out, whether it is divisible or not divisible.

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Don't worry.

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These instructions are also below in the teacher's notes.

0:50
Remember, your main goal is to write this function to

0:53
find out if one number is divisible by another.

0:58
So, here's a big hint.

1:00
Use the remainder operator.

1:02
Okay, that's all I'm gonna say.

1:05
So, go head, pause this video, take a break, stretch,

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get a drink, get comfortable, and then come back and give this problem a try.

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If, for some reason, you're not able to solve it, then come back and

1:20
I'll show you how.

1:23
So, I've created a new playground,

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and I've called this isDivisible, because that's gonna be the name of our function.

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And I've copied here the instructions.

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So, we need to create a function that accepts two int parameters.

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And the function is going to be called IsDivisible.

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So, we'll start with func, IsDivisible, and then the two parameters.

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So, the number that you're going to divide by is usually called the dividend.

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And it's going to be an Int.

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And since we want to have named parameters,

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I'm just going to put a hash there.

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And the number we're going to divide by is called the divisor.

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Remember in the instructions it said we return a bool optional, so

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let's make sure we return the bool optional, and then put in curly braces.

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So, now we need an if statement, so let's say if, dividend remainder operator.

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Divisor is equal to 0,

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then will return true,

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else will return nil.

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So, now we satisfy the bool optional return type.

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We're returning true if, indeed, the dividend is divisible by the divisor.

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If not, return no.

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So, finally, let's call this function.

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So, I'm going to use the if let syntax.

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I'll say if let result equal isDivisble.

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Now, there's a problem here,

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I see that there's an error showing up here because I did not capitalize Int.

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So let's make sure I capitalize Int here.

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And now, we can use our isDivisible function.

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So, we need to give it a dividend and a divisor.

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So, I'll say 15 and three.

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And it's gonna return a bool optional.

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So, we can do, if let result is equal to,

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so these numbers are divisible, so I'll simply print out divisible.

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Else, we'll print out Not Divisible.

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So, if we give it two numbers that aren't divisible, that says not divisible.

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[SOUND] So, there you go.

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It's pretty simple and straightforward and it utilizes pretty much everything that we

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learned throughout this course except for Tuples of course.

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But we've created a function.

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We've created named parameters.

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We're returning an option on.

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And we even use comparative operators and math operators.

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And finally we use the if let syntax to unwrap that optional.

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So, congratulations if you were able to solve this problem.

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Remember there's no right or wrong answer.

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We're at the end of this course, to recap we learned about functions,

4:49
function parameters, return types, tuple's and optional's.

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All very important concepts, in Swift that lay a good foundation.
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