exercism/elixir/hello-world

Hello World

Greet the user by name, or by saying "Hello, World!" if no name is given.

"Hello, World!" is the traditional first program for beginning programming in a new language.

Note: You can skip this exercise by running:

exercism skip $TRACK_ID hello-world

Specification

Write a Hello World! function that can greet someone given their name. The function should return the appropriate greeting.

For an input of "Alice", the response should be "Hello, Alice!".

If a name is not given, the response should be "Hello, World!"

Test-Driven Development

As programmers mature, they eventually want to test their code.

Here at Exercism we simulate Test-Driven Development (TDD), where you write your tests before writing any functionality. The simulation comes in the form of a pre-written test suite, which will signal that you have solved the problem.

It will also provide you with a safety net to explore other solutions without breaking the functionality.

A typical TDD workflow on Exercism:

1. Run the test file and pick one test that's failing.
2. Write some code to fix the test you picked.
3. Re-run the tests to confirm the test is now passing.
4. Repeat from step 1.
5. Submit your solution (exercism submit /path/to/file)

Instructions

Submissions are encouraged to be general, within reason. Having said that, it's also important not to over-engineer a solution.

It's important to remember that the goal is to make code as expressive and readable as we can. However, solutions to the hello-world exercise will not be reviewed by a person, but by rikki- the robot, who will offer an encouraging word.

Running tests

Execute the tests with:

$ elixir bob_test.exs

(Replace bob_test.exs with the name of the test file.)

Pending tests

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by commenting out the relevant @tag :pending with a # symbol.

For example:

# @tag :pending
test "shouting" do
  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end

Or, you can enable all the tests by commenting out the ExUnit.configure line in the test suite.

# ExUnit.configure exclude: :pending, trace: true

For more detailed information about the Elixir track, please see the help page.

Source

This is an exercise to introduce users to using Exercism http://en.wikipedia.org/wiki/%22Hello,_world!%22_program

Submitting Incomplete Problems

It's possible to submit an incomplete solution so you can see how others have completed the exercise.