71 lines
2.5 KiB
Markdown
71 lines
2.5 KiB
Markdown
# Hello World
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Write a function that greets the user by name, or by saying "Hello, World!" if no name is given.
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["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is the traditional first program for beginning programming in a new language.
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**Note:** You can skip this exercise by running:
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exercism skip $LANGUAGE hello-world
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## Specification
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Write a `Hello World!` function that can greet someone given their name.
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The function should return the appropriate greeting.
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For an input of "Alice", the response should be "Hello, Alice!".
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If a name is not given, the response should be "Hello, World!"
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## Test-Driven Development
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As programmers mature, they eventually want to test their code.
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Here at Exercism we simulate [Test-Driven Development](http://en.wikipedia.org/wiki/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.
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It will also provide you with a safety net to explore other solutions without breaking the functionality.
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### A typical TDD workflow on Exercism:
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1. Run the test file and pick one test that's failing.
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2. Write some code to fix the test you picked.
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3. Re-run the tests to confirm the test is now passing.
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4. Repeat from step 1.
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5. Submit your solution (`exercism submit /path/to/file`)
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## Instructions
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Submissions are encouraged to be general, within reason. Having said that, it's also important not to over-engineer a solution.
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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.
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## Setup
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Follow the setup instructions for Crystal here:
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http://exercism.io/languages/crystal
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More help installing can be found here:
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http://crystal-lang.org/docs/installation/index.html
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## Making the Test Suit Pass
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Execute the tests with:
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```bash
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$ crystal spec test_spec.cr
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```
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In each test suite all but the first test have been skipped.
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Once you get a test passing, you can unskip the next one by changing `pending` to `it`.
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## Source
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This is an exercise to introduce users to using Exercism [http://en.wikipedia.org/wiki/%22Hello,_world!%22_program](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program)
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## Submitting Incomplete Problems
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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