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Okay, and I'm gonna start

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by creating the calcTip function

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and I'm gonna start doing it with a function expression.

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So this one will receive a bill as an input, I believe.

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I think, yeah.

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So calcTip takes any bill as an input.

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So let's simply call it bill.

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And then what we want to return is the tip.

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And here I'm gonna write the exact same code

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as we did in the other challenge.

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So there's no need to explain it all again.

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It would just be a waste of time.

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So if the bill value is between 50 and 300,

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so less or equal than 300,

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and here we're using the turnary operator,

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then return the bill value times 0.15.

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So that's 15% and otherwise, it should be 20%.

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Okay?

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So the result of this turnary operator here

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will be one of these values.

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So either bill times 0.15 or times 0.2.

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And so that's gonna be the result of this operator.

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And so that's what this function will return.

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If you prefer the arrow function, we can also do that.

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So cons, calcTip equal bill

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and now we can omit the return keyword

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and do it all in one nice line.

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So now you just have to choose which one you like better.

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And I will just for the sake of readability,

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keep the first one there.

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Okay?

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But if you prefer the arrow function,

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you can just use this one.

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Great. So number two is to simply create a bills array

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with these three values.

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So bills 125, 555, and 44.

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So that was easy.

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And now we will create an array tips,

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which will contain the tip value for each bill.

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So let's do that.

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And now this is similar

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to what we did previously with calculating the ages.

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So we are going to create an array,

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and then each position will be the function call to calcTip.

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So we wanna calc the tip with bills at position zero.

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Then at position one, we want to calculate bills

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or we actually want to calculate tips based

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on bills on position one.

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And then on position two.

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And that's it.

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So let's log both the bills and to tips to the console here.

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And that gives us tips is not defined.

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So here it should be tips.

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So usually when I have an array,

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I like to give it a plural name.

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Like here bills and here tips

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because it's multiple values.

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So now that should work.

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And yeah, so these were the three tips that were calculated.

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And of course, you could have created separate values

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or actually separate variables

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for each of these function calls.

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Like tip1 equals calcTip

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with bills zero, something like this.

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And then tip2 and tip3.

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And then you could have created

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like an array with tip1, tip2, and tip3.

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Okay, so something like this.

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But my idea was to actually do it like this

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because then we don't have

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to create all these extra variables.

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So that's a lot cleaner.

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Later on in this section, we will find an even better way

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of doing this, but with what we know at this point,

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this is the best that we can do.

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So we take the first bill, calculate the tip based on that

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and put it in position number zero.

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Then we take bills at position number one, calculate the tip

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and put it in position one of this new array.

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And then we take bills at position number two

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calculate the tip and put it

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at position two of the new array.

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And so then, yeah, we end up with this.

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Lastly, let's also complete the bonus question,

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number four here.

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And all we have to do here is to create an array,

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which will have the sum of the bills and the tips.

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So that's gonna be totals.

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And now you might have tried to do something like this,

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so like bills plus tips, but as I told you

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in the previous lecture, this is simply not gonna work.

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So we cannot do any operations on arrays like this.

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It doesn't work like that.

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So let me show you the result that we would get

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from doing this.

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And so basically, each of the arrays would be transformed

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to a string, and then the two strings would be concatenated.

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So that's completely useless.

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And so the only thing that we could do

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is to say that we want bills

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at position zero plus the tips at position zero.

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And now we do this for all the three values.

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So at position one as well.

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And then at position two.

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And so this fixes this error because now in each position,

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we do actually have a real value

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because this is an actual value.

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And so with that, we can then do calculations.

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So yeah, this is correct, looks correct, right?

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And yeah, so with that, all of the four points are solved.

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And so here we conclude this part about arrays.