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Elixir Interview Questions

Last update: 23 Mar 2019, 21 QuestionsAsk Question
A Quick Overview of Elixir
Elixir Interview Questions

Best Elixir Interview Questions And Answers

Elixir is a functional and dynamic language that is designed for building scalable applications. It is based on Erlang language VM which is known for running fault-tolerant and low-latency systems. Offering useful tooling and extensible design, Elixir is supported by meta-programming and polymorphism.

  • Scalability and Extensibility
  • Fault Tolerance
  • Interactive and fast development
  • Strong metaprogramming
  • Simple syntax

The latest version is 1.7.3 which was released in August 2018.

Erlang provides two types of data types:

  • Constant data type: This data type cannot be split into primitive subtypes as it consists of Atoms and Numbers.
  • Compound data type: This data type is used to put together other data types, and it consists mainly of lists and tuples.

An open source platform, OTP is a huge set of Erlang libraries to do all kinds of tasks, from assembling ASN.1 to providing a server.

Using Catch or Try can help prevent run-time errors from causing the process to terminate. Catch Expr throws value of the expression, except when an exception occurs during the evaluation phase. Try Exprs is nothing but the enhancement of catch with the added ability to identify and handle the desired exception class.

Erlang enables to put together code into modules, which consists of functions. A module introduces local scope of functions, both Public and Private. A module is stored in a file named “.erl.” Make sure the file basename and the name of the module are the same.

A process is created by calling spawn, which forms a process and returns the pid. Here’s how you can do it:

Spawn (Module, Name, Args ) -> pid ()

The function clauses can be protected using guards, but a clause can only be protected if the guard holds it. A guard sequence is separated by a comma (,) and semicolon (;). The guard sequence can only be true when at least one guard is true.

The valid guard expressions are Atom true, Other constants, Calls to the BIFs specified, Term Comparisons, Arithmetic Expressions, Boolean Expressions, and Short-circuit Expressions.

For sending a message, you can use an exclamation mark (!) as the operator. The syntax that you can use for sending a new message is Pid ! Message.

For receiving a message, you can use Pattern Matching from the message queue receive a statement.

define ( Const, Replacement )

define ( Fun ( Var1 , Var2, …., Var ) , Replacement )

Here are the pre-defined Macros:

  • ? Module returns the name of the existing module.
  • ? Module_String returns the name of the existing module as a string.
  • ? File returns the existing file name.
  • ? Line returns the existing line number
  • ? Machine returns the existing machine name, ‘BEAM.’

The data structure that is used for storing a fixed number of elements is referred to as a record. Expressions are then translated into tuple expressions during the compilation record.

The Record is defined by the name of the record, which is followed by the field names. The record and field names should be atoms.

record (Name, { Field1 [= Value] , … FieldN [= ValueN] } )

Expr#Name.Field. This command returns the value of the mentioned field. To return the position of the specified field, you can use the command #Name.Field.

It is a small server that is used for establishing distributed communications. This name server is responsible for mapping the node names to the machine addresses.

Following are the main operators:

  • Arithmetic operators
  • Comparison operators
  • Boolean operators
  • Misc operators

It is a way to build a new string value where the code is wrapped in curly braces and ‘#’ function.

Example

                                                    

x = "Apocalypse"
y = "X-men #{x}"
IO.puts(y)
x = "Apocalypse"
y = "X-men #{x}"
IO.puts(y)

The crypto module decrypts project applications by using digital signature and hashing function and.

Example

                                                    

IO.puts(Base.encode16(:crypto.hash(:sha256, "Elixir")))

IO.puts(Base.encode16(:crypto.hash(:sha256, "Elixir")))

You can define Structs by using the defstruct. Here is how you can do it:

Example

                                                    

iex> defmodule User do
...> defstruct name: "John", age: 27
...> end
iex> defmodule User do
...> defstruct name: "John", age: 27
...> end

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