telephone screen interview questions

gistfile1.txt

A few simple question I like to ask during initial telephone screen 
interviews, over a codesharing website (e.g. codeshare.io, codebunk.com)

The aim is to get an idea of how they approach and solve problems, 
and if they have a good grasp of the language.  So...

- it's collaborative.  they can ask for help at any time.
- ask the candidate to explain their thought processes as 
  they code, if possible
- it's not important that the code is perfect (i.e. it wont be tested)

Each problem below (apart from the first example) is split into stages.
Initially they'll start of with a simple problem to solve, and depending on their
success, we progress them to the next stage which adds slightly
more complexity.

---------- Basic:  MAX ALGO --------------
// create a function which returns the largest number in an array
// note: many ways to do this.  but simplest way is const max = arr => Math.max(...arr)

---------- PEOPLE LIST -----------

------------
Step 1 (keys)
------------

{
	'id1': { firstName: 'John', lastName: 'Doe', age: 30},
	'id2': { firstName: 'John', lastName: 'Doe', age: 30},
	...
}

// create a function which takes an object like above, and returns an array of individual items

------------
Step 2: (map)
------------

// update your code so that each item in the array has only the following properies
// - id
// - name (first and last name combine)
// - index (position in the array)

------------
Step 3: (filtering and closures)
------------

// create a *new* function that allows you stipulate the minimum the age of the people returned in the array
// - it takes a number (minimum age) as an argument
// - it returns a function that takes the original array as an argument, and returns the new data when called

------------
Step 4: (reduce)
------------

// create a *new* function which takes an array of people and returns the sum of all ages.


---------- EVENT BUS --------------

Step 1: pub sub ------------

// create an event bus.  it must have the following functions:
// subscribe(eventName, handlerFunction)

Step 2: closures ------------

// update subscribe so that it returns a function which, when called, unsubscribes the event handler


----------- Soft Questions -------------

how did you get into JavaScript development / what do you like about it
how can you decide if someone is a good developer
what's the best thing you've made. (notice you've done a lot of side projects)
what makes good code
what are your thoughts on testing.  TDD
if you were to create a web application now, what tools, libraries and frameworks could you choose