The classical introductory exercise. Just say "Hello, World!".
"Hello, World!" is the traditional first program for beginning programming in a new language or environment.
The objectives are simple:
If everything goes well, you will be ready to fetch your first real exercise.
Look for a stub file having the name hello_world.go and place your solution code in that file.
To run the tests run the command go test
from within the exercise directory.
If the test suite contains benchmarks, you can run these with the --bench
and --benchmem
flags:
go test -v --bench . --benchmem
Keep in mind that each reviewer will run benchmarks on a different machine, with different specs, so the results from these benchmark tests may vary.
For more detailed information about the Go track, including how to get help if you're having trouble, please visit the exercism.io Go language page.
This is an exercise to introduce users to using Exercism http://en.wikipedia.org/wiki/%22Hello,_world!%22_program
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
package greeting
import "testing"
// Define a function named HelloWorld that takes no arguments,
// and returns a string.
// In other words, define a function with the following signature:
// HelloWorld() string
func TestHelloWorld(t *testing.T) {
expected := "Hello, World!"
if observed := HelloWorld(); observed != expected {
t.Fatalf("HelloWorld() = %v, want %v", observed, expected)
}
}
// BenchmarkHelloWorld() is a benchmarking function. These functions follow the
// form `func BenchmarkXxx(*testing.B)` and can be used to test the performance
// of your implementation. They may not be present in every exercise, but when
// they are you can run them by including the `-bench` flag with the `go test`
// command, like so: `go test -v --bench . --benchmem`
//
// You will see output similar to the following:
//
// BenchmarkHelloWorld 2000000000 0.46 ns/op
//
// This means that the loop ran 2000000000 times at a speed of 0.46 ns per loop.
//
// While benchmarking can be useful to compare different iterations of the same
// exercise, keep in mind that others will run the same benchmarks on different
// machines, with different specs, so the results from these benchmark tests may
// vary.
func BenchmarkHelloWorld(b *testing.B) {
for i := 0; i < b.N; i++ {
HelloWorld()
}
}
// This is a "stub" file. It's a little start on your solution.
// It's not a complete solution though; you have to write some code.
// Package greeting should have a package comment that summarizes what it's about.
// https://golang.org/doc/effective_go.html#commentary
package greeting
// HelloWorld should have a comment documenting it.
func HelloWorld() string {
// Write some code here to pass the test suite.
// Then remove all the stock comments.
// They're here to help you get started but they only clutter a finished solution.
// If you leave them in, reviewers may protest!
return "Hello, World!"
}
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.
Level up your programming skills with 3,450 exercises across 52 languages, and insightful discussion with our volunteer team of welcoming mentors. Exercism is 100% free forever.
Sign up Learn More