java:Duplicate local variable area Fermé

Question

Bonjour,  

public class InterfaceTest  
{ 
 interface Area 
    { 
  final static float pi=3.14F; 
  float compute(float x, float y); 
    } 
    class Rectangle implements Area  
    { 
    public float compute (float x, float y) 
    { 
   return(x*y); 
    } 
    } 
    class Circle implements Area 
    { 
       public float compute(float x, float y) 
       { 
      return (pi*x*x); 
       } 
    } 
    public static void main(String[]args) 
  { 
   Rectangle rect=new Rectangle(); 
   Circle cir=new Circle(); 
   Area area; 
   area=rect; 
   System.out.println("Area of Rectangle="+area.compute(10, 20));//area refers to cir object 
   Area area1; 
   area=cir; 
   System.out.println("Area of Circle="+area.compute(10,0 )); 
 } 
} 

j'ai écris ce prg suivant 
pendant la compilation j'ai erreur suivantes 
Exception in thread "main" java.lang.Error: Unresolved compilation problem:  
 Duplicate local variable area 
at InterfaceTest.main(InterfaceTest.java:29) 

la ligne 29 est 
   Area area; 

j'ai corrigé area par area1 

après avoir corrigé,j'ai une autre erreur apparaît 
Exception in thread "main" java.lang.Error: Unresolved compilation problems:  
 No enclosing instance of type InterfaceTest is accessible. Must qualify the allocation with an enclosing instance of type InterfaceTest (e.g. x.new A() where x is an instance of InterfaceTest). 
 No enclosing instance of type InterfaceTest is accessible. Must qualify the allocation with an enclosing instance of type InterfaceTest (e.g. x.new A() where x is an instance of InterfaceTest). 

 at InterfaceTest.main(InterfaceTest.java:24) 
ligne 24 est 
   Rectangle rect=new Rectangle(); 
Configuration: Windows 7 / Firefox 12.0

domxaline · Answer

ok,j'ai compris mon erreur,il faut ecrire ainsi

interface Area//interface defined
    {
	 final static float pi=3.14F;
	 float compute(float x, float y);
    }
    class Rectangle implements Area //interface implemented
    {
	   public float compute (float x, float y)
	   {
		 return(x*y);
	   }
    }
    class Circle implements Area //another implementation
    {
       public float compute(float x, float y)
       {
	     return (pi*x*x);
       }
    }
    public class InterfaceTest 
    {
    public static void main(String[]args)
	 {
		 Rectangle rect=new Rectangle();
		 Circle cir=new Circle();
		 Area area;// interface object
		 area=rect;//area refers to rect object
		 System.out.println("Area of Rectangle="+area.compute(10, 20));//area refers to cir object
		 System.out.println("Area of Circle="+area.compute(10,0 ));
	}
}


merci d'avance

Java:Duplicate local variable area

1 réponse

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