print type of variable in Scala

Question

Is there a neat method could print the class name of a variable in Scala?

Sometimes I see val result = foo(a,b,c) , since method foo may return different types of object and if I could print class type of result, it will be great.

Answer 1

Quick and dirty trick I often use

val result: Nothing = foo(a,b,c)

The compiler will raise an error, providing you information about the actual return type it found.

Example from the REPL

scala> val foo: Nothing = 42
<console>:1: error: type mismatch;
found   : Int(42) // <---- this is what you care about
required: Nothing
      val foo: Nothing = 42

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If you use an IDE, you may use more "sophisticated" options:

• Scala IDE: http://scala-ide.org/docs/current-user-doc/features/typingviewing/show-type-of-selection.html
• IntelliJ: How do I view the type of a scala expression in IntelliJ

Answer 2

Use Object.getClass method.

See Scala Cookbook