This is the simplest way to write the Hello World program in Crystal:
puts "Hello World"
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But if you feel like it, you can also use some object oriented programming:
```ruby
class Greeter
def initialize(@name : String )
end
def salute
puts "Hello #{@name}!"
end
end
g = Greeter.new("world")
g.salute
Or maybe with blocks:
"Hello world".each_char do |char|
print char
end
print '\n'
Each alternative might have a different performance, but luckily all of them are pretty expressive.
Ok, but what’s the purpose of learning a language if we cannot run the damn thing? Let’s see how we do this with Crystal (and let’s assume you already have it installed).
First create a file hello.cr containing your preferred choice of the previous examples.
Then type in the console:
$ bin/crystal hello.cr $ ./hello Hello World $
The compiled output is a standalone executable without any specific runtime dependency. Neat! Isn’t it?
This is the simplest way to write the Hello World program in Crystal:
Or maybe with blocks:
Each alternative might have a different performance, but luckily all of them are pretty expressive.
Ok, but what’s the purpose of learning a language if we cannot run the damn thing? Let’s see how we do this with Crystal (and let’s assume you already have it installed).
First create a file
hello.crcontaining your preferred choice of the previous examples. Then type in the console:The compiled output is a standalone executable without any specific runtime dependency. Neat! Isn’t it?