No doubt, it’s essential for understanding code to give member variables a prefix so that they can easily be distinguished from “normal” variables. I dispute this claim. It’s not the least bit necessary if you have half-decent syntax highlighting. A good IDE can let you write your code in readable English, and can show you … Read more
In the first class, sayHi() is actually an instance method which you are calling as a static method and you get away with it because sayHi() never refers to $this. Static functions are associated with the class, not an instance of the class. As such, $this is not available from a static context ($this isn’t … Read more
It’s not legal to have a struct that contains itself as a member. This is because a struct has fixed size, and it must be at least as large as the sum of the sizes of each of its members. Your type would have to have 8 bytes for the two floats, at least one … Read more
If A is a class, you can access it directly via A::$strName. class A { public static $strName=”A is my name”; } echo A::$strName; // outputs “A is my name” Update: Depending on what you have inside your array, whether its what I like to define as class objects or class literals could be a … Read more
The dot operator is used for accessing attributes of any object. For example, a complex number >>> c = 3+4j has (among others) the two attributes real and imag: >>> c.real 3.0 >>> c.imag 4.0 As well as those, it has a method, conjugate(), which is also an attribute: >>> c.conjugate <built-in method conjugate of … Read more
C++ was introduced as a superset of C. Structs were carried over from C, where the semantics of their members was that of public. A whole lot of C code exists, including libraries that were desired to work with C++ as well, that use structs. Classes were introduced in C++, and to conform with the … Read more
1.-> for accessing object member variables and methods via pointer to object Foo *foo = new Foo(); foo->member_var = 10; foo->member_func(); 2.. for accessing object member variables and methods via object instance Foo foo; foo.member_var = 10; foo.member_func(); 3.:: for accessing static variables and methods of a class/struct or namespace. It can also be used … Read more
If you have only one instance anyway, it’s best to make all variables per-instance, simply because they will be accessed (a little bit) faster (one less level of “lookup” due to the “inheritance” from class to instance), and there are no downsides to weigh against this small advantage.
Your default constructor is implicitly called here: ProxyPiece::ProxyPiece(CubeGeometry& c) { cube=c; } You want ProxyPiece::ProxyPiece(CubeGeometry& c) :cube(c) { } Otherwise your ctor is equivalent to ProxyPiece::ProxyPiece(CubeGeometry& c) :cube() //default ctor called here! { cube.operator=(c); //a function call on an already initialized object } The thing after the colon is called a member initialization list. Incidentally, … Read more
So, my question is, why I’m still able to call Go_XXX_Your_Self() and Identify_Your_Self() even after the object was deleted? Because of undefined behavior. Is this how it works in C++? (is there even after you delete it?) Because of undefined behavior. There is no guarantee that it will work the same on other implementations. Again, … Read more