constants

问题 I would like to ask what's the difference between bindConstant().annotatedWith(Names.named("keepAliveInterval")).to(60); and bind(Integer.TYPE).annotatedWith(Names.named("keepAliveInterval")).toInstance(60); I would like to load all my configuration properties with Names.bindProperties(binder(), prop); in my module and I discovered that it uses the latter one for binding properties. Thanks, regards Marek 回答1: I think reasons to use bindConstant() are: It requires that you use an annotated

问题 I'm looking to create an associative array in JS, but use constants defined as part of the class as indices. The reason I want this is so that users of the class can use the constants (which define events) to trigger actions. Some code to illustrate: STATE_NORMAL = 0; STATE_NEW_TASK_ADDED = 0; this.curr_state = STATE_NEW_TASK_ADDED; this.state_machine = { /* Prototype: STATE_NAME: { EVENT_NAME: { "next_state": new_state_name, "action": func } } */ STATE_NEW_TASK_ADDED : { // I'd like this to

问题 I've been looking for a simple answer to this question, but it seems that I can't find one. I would prefer to stay away from any external libraries that aren't already included in Python 2.6/2.7. I have 2 c header files that resemble the following: //constants_a.h const double constant1 = 2.25; const double constant2 = -0.173; const int constant3 = 13; ... //constants_b.h const double constant1 = 123.25; const double constant2 = -0.12373; const int constant3 = 14; ... And I have a python

问题 In which file should I define application-wide constants that are specific to my cakephp app? 回答1: I define them in app/config/bootstrap.php Bootstrapping CakePHP If you have any additional configuration needs, use CakePHP’s bootstrap file, found in app/Config/bootstrap.php. This file is executed just after CakePHP’s core bootstrapping. This file is ideal for a number of common bootstrapping tasks: Defining convenience functions. Registering global constants. Defining additional model, view,

问题 Is it possible to simulate constants in Javascript using closures? If so, can you please furnish me with an example? 回答1: Firefox and Chrome both support the const keyword. IE does not. So if you need constants and don't need to support IE, const isn't a bad choice. Keep in mind though, neither browser produces a runtime error when a value is assigned to a const ; the values merely remains unchanged. Otherwise, you must use functions to define constants that cannot be modified: function PI()

问题 Is it possible to simulate constants in Javascript using closures? If so, can you please furnish me with an example? 回答1: Firefox and Chrome both support the const keyword. IE does not. So if you need constants and don't need to support IE, const isn't a bad choice. Keep in mind though, neither browser produces a runtime error when a value is assigned to a const ; the values merely remains unchanged. Otherwise, you must use functions to define constants that cannot be modified: function PI()

问题 Here is what I am trying to do: class ViewController: UIViewController { let screenRect: CGRect = UIScreen.mainScreen().bounds let screenWidth = screenRect.width; let screenHeight = screenRect.height; let screenX = screenRect.origin.x let screenY = screenRect.origin.y override func viewDidLoad() { ...and so on Swift allows me to declare screenRect . However, it does not allow me to declare any other constants using this. It shows me the error: 'ViewController.Type' does not have a member

问题 As python does not have concept of constants, would it be possible to raise an exception if an 'constant' attribute is updated? How? class MyClass(): CLASS_CONSTANT = 'This is a constant' var = 'This is a not a constant, can be updated' #this should raise an exception MyClass.CLASS_CONSTANT = 'No, this cannot be updated, will raise an exception' #this should not raise an exception MyClass.var = 'updating this is fine' #this also should raise an exception MyClass().CLASS_CONSTANT = 'No, this

问题 Given the following code: const int constA = 10; const int constB = 10; function GetX(int input) { int x = constA * constB * input; ... return x; } Will the .Net compiler 'replace' the expression and put 1000 so the calculation won't be repeated over and over? In what siutation will the code run fastest: int x = constA * constB * input; int x = 10 * 10 * input; int x = 100 * input; I guess option 3 will be the faster then 2 but sometimes not the most readable option. Does the compiler

问题 Method calls can usually omit the receiver and the parentheses for the arguments: def foo; "foo" end foo # => "foo" In the case above, foo is ambiguous between method call and reference to a potential local variable. In the absence of the latter, it is interpreted as a method call. However, when the method name can in principle be a constant name (i.e., when it starts with a capital letter, and consists only of letters), it seems to need disambiguation. def Foo; "Foo" end Foo # => NameError: