declaration

I was wondering what the point of @property and @synthesise were. At the moment I use the following to declare something: //Class.m #import "Class.h" CCNode *node; @implementation //init, etc.. But I have seen others use: @property (nonatomic, etc..) CCNode* node; @synthesise (nonatomic, etc..) node; //I am not too sure on how this type of declaration works, please correct me on how it's done. They both seem to work in the same way, what are the advantages of the @property and @synthesise way? Do they do different things, if so, what? @property and @synthesize are two objective C keyword that

Am from high level OOP languages C# and Java and recently started scratching my head in C. I feel C a bit weird as equally as one feels JS is. So want to clarify below: Below gives error and that seems intuitive as it looks like incorrect syntax even in OOP languages int i=0,1,2; /* Error : expected identifier or ‘(’ before numeric constant int i = 0, 1, 2; ^ */ However below works surprisingly: int i; i = 0,1,2; //works Why is this behavior? Is their any significance to keep such behavior or just some parsing technicalities? This is actually a tricky question because it relies on the details

I am learning Google's new language Go . I am just trying stuff out and I noticed that if you declare a variable and do not do anything with it the go compiler ( 8g in my case) fails to compile with this error: hello.go:9: error declared and not used . I was suprised at this since most language compilers just warn you about unused variables but still compile. Is there anyway I can get around this? I checked the documentation for the compiler and I don't see anything that would change this behaviour. Is there a way to just delete error so that this will compile? package main import "fmt" import

I am trying to build a model that will have slightly different equations based on whether or not certain components exist (in my case, fluid ports). A code like the following will not work: parameter Boolean use_component=false; Component component if use_component; equation if use_component then component.x = 0; end if; How can I work around this? If you want to use condition components, there are some restrictions you need to be aware of. Section 4.4.5 of the Modelica 3.3 specification sums it up nicely. It says "If the condition is false, the component, its modifiers, and any connect

my_test.h #ifndef MY_TEST #define MY_TEST struct obj { int x; int y; }; class A { private: const static int a=100; const static obj b; }; const obj A::b={1,2}; #endif When compiling cpp using this header file, an error 'multiple definition of 'A::b' occurs. why is this when I have been using guard macro already? why does A::a not produce the erro? (I can't write code const static obj b={1,2} in class A ) Alok Save why is this when I have been using guard macro already? Header guards only prevent the inclusion of the header file contents more than once in the same translation unit not across

Suppose foo is an abstract class in a C++ program, why is it acceptable to declare variables of type foo* , but not of type foo ? Because if you declare a foo you must initialize/instantiate it. If you declare a *foo, you can use it to point to instances of classes that inherit from foo but are not abstract (and thus can be instantiated) You can not instantiate an abstract class. And there are differences among following declarations. // declares only a pointer, but do not instantiate. // So this is valid AbstractClass *foo; // This actually instantiate the object, so not valid AbstractClass

Well, I try to understand limitations in Const expressions in VBScript . I was not able to use anything except literals. What the docs say is: Literal or other constant, or any combination that includes all arithmetic or logical operators except Is . So, if "that includes all arithmetic or logical operators" then logically I expect I can do something like this: Const X = (1 + 2) But that brings the error "Expected literal constant". I found an interesting answer here that allows one to cheat, at some level, so the above can be done with: Execute "Const X = " & (1 + 2) But my question is about

This question already has an answer here: Can a c++ class include itself as an member? 4 answers I am new to C++ and have a question: Compare following code: class Node { public: int data; Node* x; }; and class Node { public: int data; Node x; }; I know the second part of code can't pass compile. But I want to know the reason. Is it related to memory allocation or just syntax regulation? I would be appreciate if someone can solve my question. The code in your second fragment cannot compile, because the class Node is not completely defined at the point where you declare its data member x of