constructors.cpp

#include <algorithm>
#include <iostream>
using namespace std;

class Slime {
public:
    int n;

    // Constructor is a method with the same name as the class and
    // no return type (it doesn't return anything).
    Slime(int n_)
    {
        n = n_;
    }

    // You can have multiple constructors, as long as they take
    // different kinds or number of parameters.
    Slime(int a, int b, int c)
    {
        n = c;
    }

    // With no parameters, it is the "default constructor"
    Slime()
    {
        n = 79;
    }

    // Other noteworthy constructors include the copy constructor
    // (You often don't need to type it in as the compiler will
    // make it for you in most cases.  It will fail to do that
    // when your class has some member variable it doesn't know
    // how to copy.  The compiler can copy ints just fine.)
    Slime(Slime const& rhs)
    {
        n = rhs.n;
    }

};

int main() {
    Slime s = 42;
    cout << "got: " << s.n << endl;

    Slime z(1,2,3); // When number of parameters != 1, can't use the '=' trick.
    cout << "got: " << z.n << endl;

    Slime y; // Default constructor is used here
    cout << "got: " << y.n << endl;

    Slime w = y;
    cout << "got: " << w.n << endl;

    return 0;
}