CODEWITHSUNDEEP
scala
Fahad Siddiqui
Fahad Siddiqui

Reputation: 1849

Why there are two class files generated after compiling scala code?

When we compile scala code using

scalac code.scala

There are two files created named code.class and code$.class. What is the purpose of this second file?

For reference,

object HelloWorld {
    def main (args: Array[String]) {
        println ("Hello world! This is my first scala program!");
    }
}

This is the code inside code.scala file.

Upvotes: 4

Views: 2041

Answers (2)

Gregor Raýman
Gregor Raýman

Reputation: 3081

This is the consequence of how Scala translates the Scala object to JVM constructs. An object X is translated to a class X$ with ordinary methods, ordinary inheritance etc.

As object X creates singleton in Scala, it would be nice to be able to access its public methods from Java by calling them as static methods X.someMethod(). That is why the Scala compiler creates also a class X with static methods calling the ordinary methods of the singleton instance of the class X$. Even if you don't have the Scala class X itself.

Upvotes: 8

Dmitry Meshkov
Dmitry Meshkov

Reputation: 931

Second file is for companion object, if you have both 

class Code{}
object Code{}

in your file

Upvotes: 0

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