Here is some error with my .h file which show [Error] unterminated #ifndef when I include my class template in it
You need to add a #endif to the end of your header file.
constructor
What is the best way to give a C# auto-property an initial value?
In C# 5 and earlier, to give auto implemented properties an initial value, you have to do it in a constructor. Since C# 6.0, you can specify initial value in-line. The syntax is: DefaultValueAttribute is intended to be used by the VS designer (or any other consumer) to specify a default value, not an initial value. … Read more
C++ Cannot call constructor directly in small example
I was wondering, why I cannot call a constructor. Even this small example fails to compile with the message: Code: I used the Cygwin g++ compiler in version 4.9.3-1. Thank you for your help.
What is a clean, Pythonic way to have multiple constructors in Python?
Actually None is much better for “magic” values: Now if you want complete freedom of adding more parameters: To better explain the concept of *args and **kwargs (you can actually change these names): http://docs.python.org/reference/expressions.html#calls
What’s wrong with overridable method calls in constructors?
On invoking overridable method from constructors Simply put, this is wrong because it unnecessarily opens up possibilities to MANY bugs. When the @Override is invoked, the state of the object may be inconsistent and/or incomplete. A quote from Effective Java 2nd Edition, Item 17: Design and document for inheritance, or else prohibit it: There are … Read more
Hide Utility Class Constructor : Utility classes should not have a public or default constructor
If this class is only a utility class, you should make the class final and define a private constructor: This prevents the default parameter-less constructor from being used elsewhere in your code. Additionally, you can make the class final, so that it can’t be extended in subclasses, which is a best practice for utility classes. … Read more
Pass arguments to Constructor in VBA
Here’s a little trick I’m using lately and brings good results. I would like to share with those who have to fight often with VBA. 1.- Implement a public initiation subroutine in each of your custom classes. I call it InitiateProperties throughout all my classes. This method has to accept the arguments you would like … Read more
When is it safe to call this-> in constructor and destructor
Within any non-static member function, this points to the object that the function was called on. It’s safe to use as long as that’s a valid object. Within the body of a constructor or destructor, there is a valid object of the class currently being constructed. However, if this is the base sub-object of some … Read more
Constructor of an abstract class in C#
Because there might be a standard way you want to instantiate data in the abstract class. That way you can have classes that inherit from that class call the base constructor.
Best way to do multiple constructors in PHP
I’d probably do something like this: Then if i want a Student where i know the ID: Or if i have an array of the db row: Technically you’re not building multiple constructors, just static helper methods, but you get to avoid a lot of spaghetti code in the constructor this way.