difference syntax in class constructor in C++

Question

I have a questions about two different syntax of writing class constructor.

class Sample {
 private:
     int * p;
 public:
  // first way of writing the constructor 
    Sample() 
     {p = new int; 
     }

   //second way of writing the constructor
   Sample():p(new int)
    {}

 };

Is there any difference between the two different syntax? Or are they just the same thing? Thanks !