constants

Objective C defining UIColor constants

Hi, I have a iPhone application with a few custom-defined colors for my theme. Since these colors will be fixed for my UI, I would like to define the colors in a class to be included (Constants.h and Constants.m). How do I do that? (Simply defining them does not work because UIColors are mutable, and would cause errors - Initalizer not ...

how can I get around no arrays as class constants in php?

I have a class with a static method. There is an array to check that a string argument passed is a member of a set. But, with the static method, I can't reference the class property in an uninstantiated class, nor can I have an array as a class constant. I suppose I could hard code the array in the static method, but then if I need to c...

how to use a PHP Constant that gets pulled from a database

Can you read out the name of a PHP constant from a database and use it inside of a php variable, to display the value of the constant for use in a menu? For example here's what I'm trying to accomplish In SQL: select menu_name AS php_CONSTANT where menu_id=1 the value returned would be L_HOME which is the name of a CONSTANT in a php co...

how to get a constant in java with class

basically I need to get a constant for a class however I have no instance of the object but only its class. In PHP I would do constant(XYZ); Is there a similar way of retrieving a constant in JAVA? I need it to facilitate a dynamic getMethod call Class parameterType = Class.forName(class_name); object.setProperty(field name, field valu...

PHP OOP properity constant usage

Hi there. I'm really new to OOP. I'm even not a newbie - I'm noob. So. I want to transfer my pseudo-CMS from "normal" programming, into OOP programming system. And so: private static $dsn = DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME; What here causes problem? Usage of constraints? I don't know. My editor (aptana studio) shows error ...

C++: defining maximum/minimum limits for a class

Basically what the title says... I have created a class that models time slots in a variable-granularity daily schedule (where for example the first time slot is 30 minutes, but the second time slot can be 40 minutes); the first available slot starts at (a value comparable to) 1. What I want to do now is to define somehow the maximum an...

How can I assign sequences to constants in the CONSTANTS section of a TLA+ configuration file?

I've tried CONSTANTS seq = <<5,6,7>> but TLC gives me a syntax error: Error: TLC found an error in the configuration file at line 1. It was expecting = or <- and didn't find it. I've also tried to include the Sequences module in the configuration file, to no avail. So... what do I have to do to assign a sequence? ...

How best to implement publicly accessible constants in C#

There seem to be three choices for implementing publicly accessible constants in C#. I'm curious if there are any good reason to choose one over the other or if it's just a matter of personal preference. Choice 1 - private field plus property getter private const string _someConstant = "string that will never change"; public string So...

Constants by another name

First off, I've seen this question and understand why the following code doesn't work. That is not my question. I have a constant, which is declared like; //Constants.h extern NSString * const MyConstant; //Constants.m NSString * const MyConstant = @"MyConstant"; However, in certain contexts, it's more useful to have this constant ...

RAILS_ROOT require?

I'm trying to access the RAILS_ROOT constant in a file residing in the /lib directory, but I'm not able to (uninitialized constant error). Is there something that I need to require to be able to do this? Sorry if this is a dumb question.. ...

MySQL & PHP Use of Undefined Constant

Alright, PHP is throwing this error (only in the logs): Error PHP Notice: Use of undefined constant department - assumed 'department' (line 5) PHP Notice: Use of undefined constant name - assumed 'name' (line 6) PHP Notice: Use of undefined constant email - assumed 'email' (line 7) PHP Notice: Use of undefined constant message - as...

How are constants initialized in Objective-C header files?

How do you initialise a constant in a header file? For example: @interface MyClass : NSObject { const int foo; } @implementation MyClass -(id)init:{?????;} ...

Using nested classes for constants?

What's wrong with using nested classes to group constants? Like so: public static class Constants { public static class CategoryA { public const string ValueX = "CatA_X"; public const string ValueY = "CatA_Y"; } public static class CategoryB { public const string ValueX = "CatB_X"; pu...

Why use constants in programming?

I've just been going back over a bit of C studying using Ivor Horton's Beginning C book. I got to the bit about declaring constants which seems to get mixed up with variables in the same sentence. Just to clarify, what is the difference in specifying constants and variables in C, and really, when do you need to use a constant instead of...

using structures with multidimentional tables

I have a table of structures and this structures are 2 dimentional table of constants. can you teach me on how to get the values in the table of constants. (note following is just example) typedef struct { unsigned char ** Type1; unsigned char ** Type2; } Formula; typedef struct { Formula tformula[size]; } table;...

consts and other animals

Hello i have a cpp code wich i'm having trouble reading. a class B is defined now, i understand the first two lines, but the rest isn't clear enough. is the line "B const * pa2 = pa1" defines a const variable of type class B? if so, what does the next line do? B a2(2); B *pa1 = new B(a2); B const * pa2 = pa1; B const * const pa3 = pa2;...

Ruby: how does constant-lookup work in instance_eval/class_eval?

I'm working my way through Pickaxe 1.9, and I'm a bit confused by constant-lookup in instance/class_eval blocks. I'm using 1.9.2. It seems that Ruby handles constant-lookup in *_eval blocks the same way it does method-lookup: look for a definition in receiver.singleton_class (plus mixins); then in receiver.singleton_class.superclass (...

How to manage Constants in Application

what is the best way to use Application Constants ? What i usually do is create a separate table in database of constants and reference them as foreign key in other table. In Java i use enum. But how to keep a single place of authority for constants in application and what are the different ways i can do that(like table or enum). ...

Throw exception when re-assigning a constant in Ruby?

I've long been aware that "constants" in Ruby (i.e., variable names that are capitalized) aren't really constant. Like other programming languages, a reference to an object is the only thing stored in the variable/constant. (Sidebar: Ruby does have the facility to "freeze" referenced objects from being modified, which as far as I know...

PHP How to access constant defined outside class?

I have defined some constants eg: define('DB_HOSTNAME', 'localhost', true); define('DB_USERNAME', 'root', true); define('DB_PASSWORD', 'root', true); define('DB_DATABASE', 'authtest', true); now when I try to do this: class Auth{ function AuthClass() { $this->db_link = mysql_connect(DB_HOSTNAME, DB_USERNAME, DB_PASSWORD) or die(mys...