Merge pull request #912 from jfwm2/patch-1

Update scala-for-java-programmers.md

Author: SethTisue

_overviews/tutorials/scala-for-java-programmers.md

@@ -342,7 +342,7 @@ inherited from `Object`.
       def re = real
       def im = imaginary
       override def toString() =
-        "" + re + (if (im < 0) "-" else "+") + im + "i"
+        "" + re + (if (im < 0) "" else "+") + im + "i"
     }