declaration

I am building a solution with various classes and functions all of which need access to some global consants to be able to work appropriately. As there is no const in python, what would you consider best practice to set a kind of global consants. global const g = 9.8 So I am looking for a kind of the above edit: How about: class Const(): @staticmethod def gravity(): return 9.8 print 'gravity: ', Const.gravity() ? You cannot define constants in Python. If you find some sort of hack to do it, you would just confuse everyone. To do that sort of thing, usually you should just have a module -

I found this line in stdio.h : extern struct _IO_FILE *stdin; Based on this 'extern' keyword, i assume this is just a declaration. I wonder where is stdin defined and initialized? It's defined in the source code of your C library. You typically only need the headers for compilation, but you can find the source code for many open-source standard libraries (like glibc). In glibc, it's defined in libio/stdio.c as like this: _IO_FILE *stdin = (FILE *) &_IO_2_1_stdin_; Which is in turn defined using a macro in libio/stdfiles.c like this: DEF_STDFILE(_IO_2_1_stdin_, 0, 0, _IO_NO_WRITES); The

I am new to iphone development, Now i want to access the string variable in all the view controller, but i know to declare the variables in delegate method, but i cant access it, please help me out. Mainviewcontroller-->Viewcontroller1_-->viewcontroller2-->viewcontroller3-->subwebview. i have created one main view controller and the subview class are Viewcontroller1,viewcontroller2,viewcontroller3. And the subwebview is the subclass of all the three viewcontrollers(Viewcontroller1,Viewcontroller2,Viewcontroller3). Now i want to access the string variables in subwebview from the all

I have a template class that I declare in a header with one method and no definition of that method in the header. In a .cc file, I define specializations of that method without ever declaring them in the header . In a different .cc file, I call the method for different template parameters for which specializations exist. It looks like this: foo.h: template<typename T> class Foo { public: static int bar(); }; foo.cc: #include "foo.h" template<> int Foo<int>::bar() { return 1; } template<> int Foo<double>::bar() { return 2; } main.cc: #include <iostream> #include "foo.h" int main(int argc, char

In implementing an interface it seems the common method in tutorials and literature is to declare an ivar and then set the @property then @synthesize . @interface MyClass : NSObject { NSString *myString; } @property (nonatomic, retain) NSString *myString; @end However, omitting the explicit declaration and just putting @property has the same effect. @interface MyClass: NSObject { } @property (nonatomic, retain) NSString *myString; @end So how come most people use @property and an explicit declaration? Is it bad form not to? It used to be necessary. There are two different versions of the

This is probably a really simple thing but I'm new to C++ so need help. I just want to declare an array in my C++ header file like: int lettersArr[26]; and then define it in a function in the cpp file like: lettersArr[26] = { letA, letB, letC, letD, letE, letF, letG, letH, letI, letJ, letK, letL, letM, letN, letO, letP, letQ, letR, letS, letT, letU, letV, letW, letX, letY, letZ }; but this doesn't work. Have I got the syntax wrong or something? What is the correct way to to this? Thanks a lot. Add extern to the declaration in the header file. extern int lettersArr[26]; (Also, unless you plan

I'm a VB.Net guy. (because I have to be, because the person who signs my check says so. :P) I grew up in Java and I don't generally struggle to read or write in C# when I get the chance. I came across some syntax today that I have never seen, and that I can't seem to figure out. In the following method declaration, what does < T > represent? static void Foo < T >(params T[] x) I have seen used in conjunction with declaring generic collections and things, but I can't for the life of me figure out what it does for this method. In case it matters, I came across it when thinking about some C#

I find in Apple's document Working with Blocks that the syntax to define a block that returns the result of multiplying two values: double (^multiplyTwoValues)(double, double); is different than defining a block that takes another block as an argument and returns yet another block: void (^(^complexBlock)(void (^)(void)))(void); Why is the second syntax not void (^)(void)(^complexBlock)(void (^)(void)) ? Josh Caswell This is just how C syntax works. The Block syntax is based on that of function pointers , which boils down to Dennis Ritchie's idea that "the declaration of a thing should look