Original subtitles

All right, here goes coding challenge number two,

which is gonna be all about arrays.

And in this one,

we're gonna go back to the tip calculator

that we built in the previous section.

And we're still using the same rules as before.

So we tip 15% of the bill value, if it's between 50 and 300.

And if the value is different, so outside of this range,

the tip is 20%.

And so here are your tasks.

First, write a function called calcTip,

which takes any bill value as an input,

and returns the corresponding tip.

And so that's gonna be based on the rules

that I just mentioned.

And to do this, you can actually check out the code

from the first tip calculator challenge

that we did in the last section.

So you can copy the code there.

Or if you want, you can also code this from scratch,

just to remember how to do it.

And now in number two, we're finally gonna use arrays.

So here, we're gonna create an array called bills,

which will contain the test data that we have down here.

So these are the three bill values

for which we want to calculate the tips.

And so that's what we do in point number three.

So here, we create an array called tips,

which will contain the tip value

for each of the three bills.

And this is where we're gonna use the calcTip function

that we created before.

So that's the basic challenge.

And if you wanna take it one step further,

you can even take the bonus question.

So number four here,

in which I ask you to create an array called total,

which will have the total values.

So that's the bill plus the tip.

So I hope this one isn't too hard.

Basically, it's similar to one of the examples actually,

that we did in one of the lectures about the arrays.

And once again,

I also have a hint to help you solving this one.

But if you want to try it on your own without the hint

then pause video now, and good luck.

But if you want to hint,

well, then here it goes.

So remember that an array needs a value in each position.

But that value

can actually be the returned value of a function.

So as an array value,

you can basically just call a function. Alright.

And again, that is similar

to something that we did in one of the array lectures.

So pause the video now,

and I see you with my solution in a second.

Okay, and I'm gonna start by creating the calcTip function.

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

So this one will receive a bill as an input,

I believe, I think,

yeah, so calcTip takes any bill as an input.

So let's simply call it bill.

And then what we want to return is the tip.

And here I'm gonna write the exact same code

as we did in the other challenge.

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

it would just be a waste of time.

So if the bill value is between 50 and 300,

so less or equal than 300.

And here we're using the ternary operator,

then return the bill value, times zero point 15.

So that's 15%.

And otherwise, it should be 20%.

Okay, so the result of this ternary operator here

will be one of these values.

So either bill times point 15 or times point two.

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

And so that's what this function will return.

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

So const calcTip equal bill.

And now we can omit the return keyword

and do it all in one nice line.

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

And I will just for the sake of readability.

Keep the first one there. Okay.

But if you prefer the arrow function,

you can just use this one. Great.

So number two is to simply create a bills array

with these three values.

So bills 125, five five five and 44.

So that was easy.

And now we will create an array tips,

which will contain the tip value for each bill.

So, let's do that.

And now this is similar to what we did previously

with calculating the ages.

So we are going to create an array,

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

So we want to calc the tip with bills at position zero.

Then at position one, we want to calculate bills.

Or we actually want to calculate tips based on bills

on position one, and then on position two. And that's it.

So let's log both the bills

and the tips to the console here.

And that gives us tips is not defined.

So here, it should be tips.

So usually when I have an array,

I like to give it a plural name,

like here bills and here tips.

So because it's multiple values,

so now that should work.

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

And of course, you could have created separate values,

or actually separate variables

for each of these function calls,

like tip one equals calcTip with bills, zero,

something like this.

And then tip two and tip three.

And then you could have created

like an array with tip one, tip two and tip three.

Okay, so something like this.

But my idea was to actually do it like this,

because then we don't have to create

all these extra variables. So that's a lot cleaner.

Later on in the section,

we will find an even better way of doing this.

But with what we know, at this point,

this is the best that we can do.

So we take the first bill,

calculate the tip based on that

and put it in position number zero,

then we take bills at position number one

calculate the tip and put it in position one

of this new array,

and then we take bills at position number two,

calculate the tip

and put it at position two of the new array.

And so then, now we end up with this.

Lastly, let's also complete the bonus question

number four here.

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

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

So that's gonna be totals.

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

So like bills plus tips.

But as I told you in the previous lecture,

this is simply not gonna work.

So we cannot do any operations on arrays like this,

it doesn't work like that.

So let me show you the result that we would get

from doing this.

And so basically, each of the arrays would be transformed

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

So that's completely useless.

And so the only thing that we could do

is to say that we want bills at position zero,

plus the tips at position zero.

And now we do this for all the three values.

So at position one as well.

And then at position two.

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

we do actually have a real value,

because this is an actual value.

And so with that, we can then do calculations.

So, yeah, this is correct. Looks correct. Right.

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

And so here we conclude this part about arrays