Difference between implicit conversion and explicit conversion [duplicate]

Answer 1

You Mean Casting? Implicit mean you pass an instance of type, say B, that inherits from a type, say A as A.

For example:

Class A;
Class B extends A;

function f(A a) {...};

main() {
  B b = new B;
  f(b); // <-- b will be implicitly upcast to A.
}

There are actually other types of implicit castings - between primitives, using default constructors. You will have to be more specific with your question.

implicit with default constructor:

class A { 
  A (B b) { ... };
}

class B {};

main() {
  B b = new B();
  A a = b; // Implict conversion using the default constructor of A, C++ only.
}