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https://github.com/mosnad-web01/abdulmajeed-phase-1-first-class-functions-lab


https://github.com/mosnad-web01/abdulmajeed-phase-1-first-class-functions-lab

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README 

        
https://mosnad-web01.github.io/Abdulmajeed-phase-1-first-class-functions-lab/

# JavaScript Advanced Functions: First-Class Functions Lab



## Learning Goals



- Assign functions to a variable.

- Store functions in a data structure.

- Write functions that return other functions.

- Pass a function to another function.

- Call a function returned by another function.



## Introduction



Functions are a very important part of JavaScript, and you will use them all the

time. Without functions, we wouldn't get anything done! In this lab, we'll take

a look at how we can use functions as first-class objects to pass them around,

store them in variables and data structures, and return them from other

functions.



For this lab, you will continue working on functions for our scooter-taxi

client, Scuber.



## Instructions



**Fork and clone** this lab into your local environment. Navigate into its

directory in the terminal, then run `code .` to open the files in Visual Studio

Code.



Using the tests to guide you, create the following deliverables:



- `returnFirstTwoDrivers()` — Declare the variable `returnFirstTwoDrivers` with

  `const` and assign an anonymous function to it. The assigned function should

  take one argument, an array containing the names of Scuber's drivers, and

  return a new array containing the **first** two drivers in the array:



```js

returnFirstTwoDrivers(['Antonia', 'Nuru', 'Amari', 'Mo'])

// => ['Antonia', 'Nuru']

```



- `returnLastTwoDrivers()` — Declare a variable with `const` that is assigned an

  anonymous function. The assigned function should take one argument, an array

  containing the names of Scuber's drivers, and return a new array containing

  the **last** two drivers in the array:



```js

returnLastTwoDrivers(['Antonia', 'Nuru', 'Amari', 'Mo'])

// => ['Amari', 'Mo']

```



- `selectingDrivers` — This is an array containing two elements: the two

  functions that we previously defined (`returnFirstTwoDrivers()` and

  `returnLastTwoDrivers()`).

- `createFareMultiplier()` — This is a higher-order function that takes in one

  argument, an integer, and returns a function that will multiply a fare for a

  ride accordingly. For example, if `createFareMultiplier()` receives an argument

  of `4`, it will return a function that takes in a fare as an argument and

  quadruples the fare.

- `fareDoubler()` — Declare a variable with `const` and assign a function

  returned by `createFareMultiplier()` to it. Invoke `createFareMultiplier()` in

  such a way that the new `fareDoubler()` function accepts a fare as its lone

  argument and doubles it.

- `fareTripler()` — Declare a variable with `const` and assign a function

  returned by `createFareMultiplier()` to it. Invoke `createFareMultiplier()` in

  such a way that the new `fareTripler()` function accepts a fare as its lone

  argument and triples it.

- `selectDifferentDrivers()` — This function takes two arguments, an array of

  the names of Scuber's `drivers` and either the `returnFirstTwoDrivers()` or

  `returnLastTwoDrivers()` function. Based on these two arguments,

  `selectDifferentDrivers()` will return either the first two drivers or the

  last two drivers.



When you're done, remember to commit and push your changes up to GitHub, then

submit your work to Canvas using CodeGrade.



## Resources



- [Wikipedia: First-class function](https://en.wikipedia.org/wiki/First-class_function)

- [MDN: Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions)

- [TypeOfNaN: What is a Higher-Order Function?](https://typeofnan.dev/what-is-a-higher-order-function/)