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copied!<p>(Assuming you want the question of how to resolve overloads when you need to pass a null):</p> <p>Just as you would in Java, by ascribing the type corresponding to the overload you wish to invoke (in Java you'd cast, but it amounts to the same thing: an assertion of the static type to assign to the <code>null</code>):</p> <pre><code>scala> object O { def m(i: Int, s: String): String = s * i; def m(i: Int, l: List[String]): String = l.mkString(":") * i } defined module O scala> O.m(23, null) <console>:7: error: ambiguous reference to overloaded definition, both method m in object O of type (i: Int,l: List[String])String and method m in object O of type (i: Int,s: String)String match argument types (Int,Null) O.m(23, null) ^ scala> O.m(23, null: String) res4: String = nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull scala> O.m(23, null: List[String]) java.lang.NullPointerException at O$.m(<console>:5) at .<init>(<console>:7) at .<clinit>(<console>) at RequestResult$.<init>(<console>:9) at RequestResult$.<clinit>(<console>) at RequestResult$scala_repl_result(<console>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1$$anonfun$apply$18.apply(Interpreter.scala:981) at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1$$anonfun$apply$18.apply(Interpreter.scala:981) at scala.util.control.Exception$Catch.apply(Exception.scala:7... scala> </code></pre>

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