constructor

问题 i have a function for login controls. if user didnt login it redirects to login.php in my controller i have to many functions and this functions represents pages in website. so do i have to call $this->is_logged_in(); function in each function. for example: class Admin extends CI_Controller{ function index(){ $this->is_logged_in(); // works fine like this $this->load->view('admin/welcome_message'); } function users(){ $this->is_logged_in(); // works fine like this $this->load->view('admin

问题 Hi this is from a challenge I was working on. Is there any way i can add the introduce method to the personStore object without using the keyword this. Any insight is greatly appreciated. Using Object.create Challenge 1/3 Inside personStore object, create a property greet where the value is a function that logs "hello". Challenge 2/3 Create a function personFromPersonStore that takes as input a name and an age. > When called, the function will create person objects using the Object.create

问题 I have two files: MyStringLog.java (which extends ArrayStringLog) and TestDriver.java in the same directory. Why doesn't TestDriver.java recognize the MyStringLog constructor from the MyStringLog class? In TestDriver.java I declare: MyStringLog animals = new MyStringLog("animals"); This is supposed to construct a new MyStringLog object named animals, but I get 2 errors when I compile, both, that MyStringLog symbol is not found. ArrayStringLog.java: http://pastebin.com/Z624DRcm MyStringLog

问题 I'm trying to Create a class that holds a location,Including the following methods: Setters (mutators) for each of the data fields For the location name, you should use the trim() method to remove any leading or trailing blank spaces. Getters (accessors) for each of the data fields Constructor: You should have only one constructor that takes the place name, the latitude, and the longitude. You may expect that the data will be valid, although the strings may need to be trimmed. public class

问题 I'm trying to implement an immutable data class with more than one constructor. I felt that something like this should be possible: data class Color(val r: Int, val g: Int, val b: Int) { constructor(hex: String) { assert(Regex("#[a-fA-F0-6]{6}").matches(hex), { "$hex is not a hex color" } ) val r = hex.substring(1..2).toInt(16) val g = hex.substring(3..4).toInt(16) val b = hex.substring(5..6).toInt(16) this(r,g,b) } } Of course, it isn't: Kotlin expects the call to the main constructor be

问题 Let's say you start off with this stub: [<Serializable>] type Bounderizer = val mutable _boundRect : Rectangle new (boundRect : Rectangle) = { _boundRect = boundRect ; } new () = { _boundRect = Rectangle(0, 0, 1, 1); } new (info:SerializationInfo, context:StreamingContext) = { // to do } interface ISerializable with member this.GetObjectData(info, context) = if info = null then raise(ArgumentNullException("info")) info.AddValue("BoundRect", this._boundRect) // TODO - add BoundRect property

问题 I am trying to write a method GetDynamicConstructor<T> which will return, essentially, a smart constructor for the given class. It will accept an array of strings as parameters and parse them as the appropriate type (given existing constructor data). public void Init() { DynamicConstructor<MyClass> ctor = GetDynamicConstructor<MyClass>(); MyClass instance = ctor(new string[] { "123", "abc" }); // parse "123" as int } public delegate T DynamicConstructor<T>(string[] args); public

问题 There is this Q&A about Abstract constructor types in TypeScript, which is a question I would like to know the answer to: Abstract constructor type in TypeScript Unfortunately, the accepted answer is little more that an unexplained one-liner: type Constructor<T> = Function & { prototype: T } It appears that this answer is good enough for the asker, it is the accepted answer, but I'm unable to understand how the answer applies to the question. I've tried asking in the comments, and I've tried

问题 I'm having a memory violation error and I don't know where it comes from. My question is : am I allowed to get the address of a class member while inside the constructor initialization list so that I can pass it to an object that needs a reference to it ? For example : class A { }; class ReferencesA { A * const pA; ReferencesA( A * ptrA ) : pA( ptrA ) { } }; class B { A a; ReferencesA referencesA; B() : referencesA( & a ) { } }; Is is safe to & a inside the constructor initialization list ?

问题 This question already has answers here : Why can templates only be implemented in the header file? (16 answers) Closed 5 years ago . I get linker error if I define constructor\destructor of template class outside the class. Is it not allowed? I use Visual studio 2010. error 1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall Tree::~Tree(void)" (??1?$Tree@H@@QAE@XZ) referenced in function _main 1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall