How can I access the last result in Scala REPL?

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旧时难觅i
旧时难觅i 2021-01-04 01:02

In python REPL I can do things like:

>>> [1,2,3,4]
[1, 2, 3, 4]
>>> sum(_)
10

In clojure REPL I can do this:

         


        
3条回答
  •  一生所求
    2021-01-04 01:22

    You can refer to the previous output as resN for some N. You've probably noticed that in the Scala REPL, results are printed in the form resN: Type = value:

    Welcome to Scala version 2.9.1.final (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_24).
    Type in expressions to have them evaluated.
    Type :help for more information.
    
    scala> List(1,2,3,4)
    res0: List[Int] = List(1, 2, 3, 4)
    
    scala> "Hello!"
    res1: java.lang.String = Hello!
    

    Well, that resN is a real variable name. In this example, you can refer to the list as res0 and the string as res1 for (at least as far as I know) as long as the REPL is open:

    scala> (res0.toString + res1) toLowerCase
    res2: java.lang.String = list(1, 2, 3, 4)hello!
    

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