Declare a higher order function called getLength() that takes two
parameters; `arr` and `cb`, it should pass the length of the array
into the callback and invoke it.

Create a higher order function called last()that takes two parameters;
`arr` and `cb`, it should pass the last item of the array into the
callback and invoke it.

Create a higher order function called sumNums() that takes three
parameters; `x`, `y` and `cb`, it should pass the sum of `x` and
`y` into the callback and invoke it.

Create a higher order function called multiplyNums() that takes three
parameters; `x`, `y` and `cb`, it should pass the product of `x` and
`y` into the callback and invoke it.

Create a higher order function called contains() that takes three
parameters; `item`, `list` and `cb`, it should pass `true` or `false`
into the callback based on whether or not `item` is present in `list`
and invoke it.

Combine the first and last names into a new array called fullName.
Convert each first name into all caps and log the result. Return an
array named largeShirts that contains info about the runners that
have a shirt size of L and log the result. Add up all the donations
into a ticketPriceTotal and log the result.

Extract runners with donations greater than 200 into a goldenDonors
array and log the result. Extract all runners email into an emailList
array and log the result to console. Assign the sum of the golden
donations to a variable called, goldenDonationTotal and log the result
to console.

Write a closure that return a function that when invoked decrements
and returns a startCount variable.

Create a counter function that returns a function, which when invoked
increments and returns a counter variable. Create another counter
function with an object that can increment and decrement a counter
variable and return it.

Create a called `removeDuplicates` that removes all duplicate values
from a given array parameter and pass the duplicate free array to a
callback function parameter.

WEBEU2 - JavaScript II - James Eneh 🇳🇬