Write a C++ program that prompts the user for the radius of a circle then calls inline function circleArea() to calculate the area of that circle :     #include<stdio.h>
    #include<iostream>
    #include<math.h>
    using namespace std;

    class Circle
    {
	   private:
		    float radius;
	   public:
		  inline void circleArea(float)
		
		    void input()
		   {
			cout<<"\nEnter the radius of circle";
			cin>>radius;
		   }
		
	
		  Circle()
		   {
			float radius=0.0;
		 }
	   };
	   void circleArea()
	   {
		float a,r;
		a=(3.14*r*r);
		
	    }
	   int main()
	  {
	   Circle c;
	   c.input();
	   c.circleArea();
	
     }

Here i dont undestand how to put inline function,and i am not getting any output,my output shows blank space after putting the value of radius please help..