Kotlin
Learn how to solve CodeCrafters challenges in Kotlin
New to Kotlin? We recommend checking out Kotlin Koans to get up to speed.
Local development
To run the code for your challenge locally, you’ll need mvn
installed. Our test runners use mvn
version 3.9.5
(as of November 2023).
The script for your challenge (like ./your_bittorrent.sh
) will automatically compile your code using mvn package
before executing it.
File structure
- The files for your solution are placed in the
src/main/kotlin
directory. src/main/kotlin/Main.kt
contains themain
function, which is what the test runner executes.
Adding more files
You can add more files and directories to src/main/kotlin
. The test runner will include them when compiling your code.
For example, if you added a file at src/main/kotlin/Foo.kt
, you could use it like so:
By default, all files in src/main/kotlin
are in the default
package. If you want to extract files into a different package,
you’ll need to add a package
declaration to the top of the file.
Let’s say you wanted to extract Foo.kt
into the com.example.foo
package. You’d add the following to the top of Foo.kt
:
Adding dependencies
You can add dependencies to your project by adding them to your pom.xml
file.
For example, to add the gson library, add the following to the <dependencies>
section in your pom.xml
:
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.6</version>
</dependency>
When you push your code next, the runner will automatically download the dependency.
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