Your first script

Hello hello.exs

Scripts are plain text files with the exs extension. Create a file named hello.exs in an empty folder and put one line inside:

hello.exs

IO.puts("Hello, Elixir")

elixir hello.exs

Run the script by passing its name to the elixir command:

elixir hello.exs

Hello, Elixir

The toolchain reads the file from top to bottom and prints the greeting.

IO.puts strings

IO.puts prints strings, and the <> operator joins two strings into one. Interpolation with #{} drops a value straight into a string:

name = "Ada" IO.puts("Hello, " <> name) IO.puts("2 + 2 is #{2 + 2}")

Hello, Ada

2 + 2 is 4

Common beginner mistakes

Three mistakes catch almost every beginner. First, a bare puts fails because Elixir keeps printing inside the IO module, so always write IO.puts.

Second, single quoted text is a charlist rather than a string, so use double quotes for all text in this course. Third, the run command needs the full file name with its extension, or the toolchain finds nothing.

Next: Variables

Article author: Arthur Isaev