The implict in Scala

1. As an implicit parameter

1 ObjectTest {2 3 def main (args:array[string]) {4 Import Fruitcolor._5Fruit.get ("Apple")6   }7 }8 9 Objectfruit{Ten def get (fruitname:string) (implicit fruitcolor:string): Unit ={ Oneprintln (S"$fruitName color is $fruitColor") A   } - } -  the Objectfruitcolor{ -ImplicitValcolor:string="Red" -}

2 Implict Class

Within the visual scope of a class, the primary constructor can be implicitly converted.

Limit: 1.implict class must be defined in Trait/class/object

2. There can be only one non-implicit parameter in the constructor

3. Within the scope of the Implict class, you cannot have method, member, and object of the same name.

Object main{  def Main (args:array[string]) {    import helpers._    5 times println ("  Test")  }}object  helpers{  class  Intwithtimes (X:int) {    def times[a] (f: = A): Unit ={      def Loop (current:int): Unit ={        if (current>0) {          F          loop (current-1)        }      }      Loop (x)    }   }}

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3.implict Object

Note: Implicit values cannot be in the top-level position and need to be used as a member

Objectmain{def Sum[a] (Xs:list[a]) (implicit m:monoid[a]): a={if(xs.isempty) M.unitElseM.add (Xs.head,sum (xs.tail))} implicitObjectIntmonoid extends monoid[int]{def add (x:int,y:int): Int=x+y def unit:int=0} implicitObjectStringmonoid extends monoid[string]{Overridedef unit:string =""    Overridedef Add (x:string, y:string): String = x concat y} def main (args:array[string]) {println (sum (List (1,2,3)) println (sum (List ) ("a","b","C")))  }}Abstract classsemigroup[a]{def Add (x:a,y:a): A}Abstract classMonoid[a] extends semigroup[a]{def unit:a}

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Reference:

1.http://docs.scala-lang.org/overviews/core/implicit-classes.html

2.http://docs.scala-lang.org/tutorials/tour/implicit-parameters.html

The implict in Scala