main.erl

 main(_) -> io:fwrite("Hello, World!").

Erlang Online Compiler

Write, Run & Share Erlang code online using OneCompiler's Erlang online compiler for free. It's one of the robust, feature-rich online compilers for Erlang language, running on the latest version 21. Getting started with the OneCompiler's Erlang compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Erlang and start coding.

About Erlang

Erlang is a special niche functional programming language by Ericcson and first appeared in the year 1986. Many Big companies are using Erlang like Whatsapp, Facebook, Amazon, RabbitMQ and many others and ofcourse Ericsson.

Key Features

Open source
Mini operating system with a number of interesting features
Initially designed as phone language but later it's used in variety of applications.
Largely parallel and distributed
updates can be made with no downtime at all
Super clean error handling model
Automatic application migration.

Syntax help

Variables

Variables syntax is as follows

variable-name = value

Data types

Data type	Usage	Description
Numeric	start() -> `io:fwrite("~w",[10+10])`	Erlang supports both integer and float values.
Atom	start() -> io:fwrite(true)	Atoms should start with lower case leters and can contain lowercase and uppercase characters, numbers, `_` and `@`. You can also put atom in single quotes
Boolean	start() -> io:fwrite(10 =< 8)	Output will be either true or false based on the values given
Bit String	str = <<10,20>>	Strings are enclosed in << >> and are used to store untyped memory
Lists	`[1,2,3]`	Lists is a compound data type with Variable number of elements.
Tuples	t = {apple, 100, {orange,50}}	Tuple is a compound data type with fixed number of elements.
Map	map = #{name => onecompiler, message => Learning}	Map is a compound data type with a variable number of key-value pairs

Loops

1. If-Else:

If the condition is true then true-statement will get executed else false-statement.

if
condition ->
   true-statement;
true ->
   false-statement
end.

2. Case:

If the value is equal to any of the values(value1,value2,..Valuen) then corresponding statements will get executed.

case value of
   value1 -> statement1;
   value2 -> statement2;
   valuen -> statementn
end.

Note:

As Erlang is a functional programming language, there are no direct constructs for while, for and other loops. Recursion is the technique followed to implement loops in Erlang.