Elixir

Question 1

terminal line for the console?

Answer 1

iex

Question 2

Framework used with Elixir?

Answer 2

Phoenix

Question 3

Which virtual machine do Elixir programs compile to?

Answer 3

Erlang

Question 4

How do Erlang and Elixir work together?

Answer 4

The Erlang VM runs as one operating system process, and by default runs one OS thread per core. Elixir programs use all CPU cores.

Question 5

Why is Erlang faster than other platforms?

Answer 5

Erlang is faster than other platforms because it doesn’t allow mutability or shared memory by default.

Question 6

Erlang is a _____ programming language.

Answer 6

functional

Question 7

How does functional programming treat computation?

Answer 7

As the evaluation of functions, and avoids mutable state and data. immutable data structures and single assignment variables

Question 8

Main difference between Obeject & Functional Programming?

Answer 8

Object doesn’t enforce isolated state. Values can be mutated in place. Functional has immutable data structures and single assignment variables

Question 9

What is the Elixir match operator?

Answer 9

the = operator is the match operator. It enables us to assign and then match values

iex> {a, b, 42} = {:hello, “world”, 42}

Question 10

What is Mix and what does it do?

Answer 10

it’s an Elixir development tool

Creates projects

Compiles projects

Runs ‘tasks’ (i.e running tests or generating documentation)

Manages dependencies

Question 11

What is the CL for generating new Elixir project?

Answer 11

mix new name-of-project

Question 12

How is code organized in Elixir?

Answer 12

In modules. A collection of different methods or functions.

Question 13

CL to compile and run your project in the Elixir console?

Answer 13

iex -S mix

Question 14

What is CL to access the Elixir console?

Answer 14

iex = interactive Elixir shell

Question 15

How do you call a method on a module?

Answer 15

with .

you can use or leave out the parentheses

Cards.hello
Cards.hello()

Question 16

Which is convention? single or double quotes

Answer 16

double quotes

Question 17

console CL for refreshing your console with updated code?

Answer 17

recompile

Question 18

Main diff between object and functional programming?

Answer 18

With functional, you can’t create classes or copies or instances of a class. It’s just a collection of methods in a module. You pass in data and the module applies a method to that data.

But you do have assignment variables

Question 19

Term for number of arguments a method accepts?

Answer 19

arity

Method as an ‘arity’ of 1 (argument)

Question 20

How does Elixir handle variables?

Answer 20

Variables are immutable. We never modify any existing data. We create and return a new one/copy.

Question 21

Syntax for a “for” loop?

Answer 21

for element

Question 22

Syntax for string interpolation?

Answer 22

{ }

Question 23

What does a nested for loop produce?

Answer 23

nested lists/arrays

Question 24

Method to check if a list contains a particular element?

Answer 24

Enum.member?(list, element)

Question 25

What is a tuple?

Answer 25

Like an array where each index has a special meaning.

Uses { }

Question 26

Method to randomly separate a list by a given value?

Answer 26

Enum.split(list, num)

returns a tuple with two lists. separated list at index 0, rest of the list at index 1)

Question 27

How is Erlang code identified?

Answer 27

with a colon :

Question 28

How do Elixir and Erlang work together?

Answer 28

Elixir sits on top of Erland and we can call Erlang code at any time.

Question 29

Elixir version of an if statemement?

Answer 29

case variable do
:ok -> code
:error -> code
end

Question 30

What are atoms?

Answer 30

premitive variables to handle status and control flows. similar to strings, but an atom is codified.

:ok
:error

Question 31

What does _variable mean in pattern matching?

Answer 31

We know there is going to be an element there in the pattern match, but we don’t want to use it (but we still have to put it in for the purpose of pattern matching)