What is a non-default (or “alternative”) constructor?

If we define a non-default constructor, will C++ generate an implicitly defined default constructor?

What is this and when do we use the this keyword?

Trace the output of the following code and explain which constructors are called at each step and why?

 #include <iostream>
	
 class Student {
 public:
     Student() {
         std::cout << "Default constructor called" << std::endl;
     }
     Student(int id) {
         std::cout << "Non-default constructor called for ID " << id << std::endl;
     }
 };
	
 int main() {
     Student s1(10);
     Student* s2 = new Student;
     Student* s3 = new Student(20);
     delete s2;
     delete s3;
     return 0;
 }

What is a destructor?

A destructor will automatically release memories that are allocated in the constructor- true or false?