Search Results

Search found 1449 results on 58 pages for 'oop'.

Page 31/58 | < Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >

  • Automatically selecting and creating class objects

    - by Omin
    Lets say that we have a box class: class Box { private int width; private int height; //Box Constructor public Box( int height ) { this.height = height; width = 450; } } and a series of Box objects in our main: Box Box1 = new Box(147); Box Box2 = new Box(178); Box Box3 = new Box(784); Is there a way to use a "for" loop to go through these objects? Also, how would you make the computer create class objects for us? eg. create 10 objects using: for( int i=0; i>10; i++) { //method }

    Read the article

  • Would this constructor be acceptable practice?

    - by Robb
    Let's assume I have a c++ class that have properly implemented a copy constructor and an overloaded = operator. By properly implemented I mean they are working and perform a deep copy: Class1::Class1(const Class1 &class1) { // Perform copy } Class1& Class1::operator=(const Class1 *class1) { // perform copy return *this; } Now lets say I have this constructor as well: Class1::Class1(Class1 *class1) { *this = *class1; } My question is would the above constructor be acceptable practice? This is code that i've inherited and maintaining.

    Read the article

  • When do you use metaclasses?

    - by johannix
    Just started looking into metaclasses and while they seem powerful, I can think of other ways to accomplish the same type of thing. I was wondering when metaclasses have been found to be the right answer and why.

    Read the article

  • Is it OK to write a constructor which does nothing?

    - by Roman
    To use methods of a class I need to instantiate a class. At the moment the class has not constructor (so I want to write it). But than I have realized that the constructor should do nothing (I do need to specify values of fields). In this context I have a question if it is OK to write constructor which does nothing. For example: public Point() { }

    Read the article

  • How can i split up a component using cfinclude and still use inheritance?

    - by rip747
    Note: this is just a simplized example of what i'm trying to do to get the idea across. The problem I'm having is that I want to use cfinclude inside cfcomponent so that i can group like methods into separate files for more manageability. The problem I'm running into is when i try to extend another component that also uses cfinclude to manage it's method as demostrated below. Note that ComponentA extends ComponentB: ComponentA ========== <cfcomponent output="false" extends="componentb"> <cfinclude template="componenta/methods.cfm"> </cfcomponent> componenta/methods.cfm ====================== <cffunction name="a"><cfreturn "componenta-a"></cffunction> <cffunction name="b"><cfreturn "componenta-b"></cffunction> <cffunction name="c"><cfreturn "componenta-c"></cffunction> <cffunction name="d"><cfreturn super.a()></cffunction> ComponentB ========== <cfcomponent output="false"> <cfinclude template="componentb/methods.cfm"> </cfcomponent> componentb/methods.cfm ====================== <cffunction name="a"><cfreturn "componentb-a"></cffunction> <cffunction name="b"><cfreturn "componentb-b"></cffunction> <cffunction name="c"><cfreturn "componentb-c"></cffunction> The issue is that when i try to initialize ComponentA I get an the error: "Routines cannot be declared more than once. The routine a has been declared twice in different templates." The whole reason for this is because when you use cfinclude it's evaluated at RUN TIME instead of COMPILE TIME. Short of moving the methods into the components themselves and eliminating the use of cfinclude, how can i get around this or does someone have a better idea splitting up large components?

    Read the article

  • Why does PHP 5.2 disallow abstract static class methods?

    - by Artem Russakovskii
    After enabling strict warnings in PHP 5.2, I saw a load of strict standards warnings from a project that was originally written without strict warnings: Strict Standards: Static function Program::getSelectSQL() should not be abstract in Program.class.inc The function in question belongs to an abstract parent class Program and is declared abstract static because it should be implemented in its child classes, such as TVProgram. I did find references to this change here: Dropped abstract static class functions. Due to an oversight, PHP 5.0.x and 5.1.x allowed abstract static functions in classes. As of PHP 5.2.x, only interfaces can have them. My question is: can someone explain in a clear way why there shouldn't be an abstract static function in PHP?

    Read the article

  • Graphic editor opensource project example on c++ underlying composite pattern

    - by G-71
    Can you tell me when I can see a some opensource project (only project on C++ language), which is simple graphic editor, ?ontaining following primitive (for example): an ellipse, a rectangle, a line. And desirable, that to be able to group this primitive in one primitive (for example, Word Grouping - Group). Composite pattern use is desirable in this project. I want to see how to organize classes, but more serious for me is to see how organize grouping operation. I searched for it on codeproject.com codeproject.com, codeplex.com, but not found this. I have already some source http://pastebin.com/xe4JF5PW But in my opinion, this code is dirty and ugly. Therefore, I want to see some opensource project for example. Thanks!

    Read the article

  • Access to an "upper" instance of a class from another instance of a different class

    - by BorrajaX
    Hello everyone! I have a tricky question and probably what I want to do is not even possible but... who knows... Python seems very flexible and powerful... I'd like to know if there's a way to access to the class (or its fields) where an object is instanciated. Let's say I have: def Class1: def __init__(self): self.title = "randomTitle" self.anotherField = float() self.class2Field = Class2() and the class whose type will be the class2Field: def Class2: def __init__(self): self.field1 = "" self.field2 = "" # . . . # I'd like to know if there's a way to access the instance of Class1 from the instance of Class2 that is declared in Class1 (meaning, accessing the fields of Class1 from the variable self.class2Field in that Class1 instance) I know I can always change the init in Class2 to accept a Class1 parameter, but I'd like to know if there's another way of "climbing" through the class hierachy... Thank you very much!

    Read the article

  • Javascript: Access the right scope "under" apply(...)

    - by Chau
    This is a very old problem, but I cannot seem to get my head around the other solutions presented here. I have an object function ObjA() { var a = 1; this.methodA = function() { alert(a); } } which is instantiated like var myObjA = new ObjA(); Later on, I assign my methodA as a handler function in an external Javascript Framework, which invokes it using the apply(...) method. When the external framework executes my methodA, this belongs to the framework function invoking my method. Since I cannot change how my method is called, how do I regain access to the private variable a? My research tells me, that closures might be what I'm looking for.

    Read the article

  • Best way to track the stages of a form across different controllers - $_GET or routing

    - by chrisj
    Hi, I am in a bit of a dilemma about how best to handle the following situation. I have a long registration process on a site, where there are around 10 form sections to fill in. Some of these forms relate specifically to the user and their own personal data, while most of them relate to the user's pets - my current set up handles user specific forms in a User_Controller (e.g via methods like user/profile, user/household etc), and similarly the pet related forms are handled in a Pet_Controller (e.g pet/health). Whether or not all of these methods should be combined into a single Registration_Controller, I'm not sure - I'm open to any advice on that. Anyway, my main issue is that I want to generate a progress bar which shows how far along in the registration process each user is. As the urls in each form section can potentially be mapping to different controllers, I'm trying to find a clean way to extract which stage a person is at in the overall process. I could just use the query string to pass a stage parameter with each request, e.g user/profile?stage=1. Another way to do it potentially is to use routing - e.g the urls for each section of the form could be set up to be registration/stage/1, registration/stage/2 - then i could just map these urls to the appropriate controller/method behind the scenes. If this makes any sense at all, does anyone have any advice for me?

    Read the article

  • Creating an interface and swappable implementations in python

    - by Blankman
    Hi, Would it be possible to create a class interface in python and various implementations of the interface. Example: I want to create a class for pop3 access (and all methods etc.). If I go with a commercial component, I want to wrap it to adhere to a contract. In the future, if I want to use another component or code my own, I want to be able to swap things out and not have things very tightly coupled. Possible? I'm new to python.

    Read the article

  • How to "wrap" implementation in C#

    - by igor
    Hello, I have these classes in C# (.NET Framework 3.5) described below: public class Base { public int State {get; set;} public virtual int Method1(){} public virtual string Method2(){} ... public virtual void Method10(){} } public class B: Base { // some implementation } public class Proxy: Base { private B _b; public class Proxy(B b) { _b = b; } public override int Method1() { if (State == Running) return _b.Method1(); else return base.Method1(); } public override string Method2() { if (State == Running) return _b.Method2(); else return base.Method2(); } public override void Method10() { if (State == Running) _b.Method10(); else base.Method10(); } } I want to get something this: public Base GetStateDependentImplementation() { if (State == Running) // may be some other rule return _b; else return base; // compile error } and my Proxy's implementation will be: public class Proxy: Base { ... public override int Method1() { return GetStateDependentImplementation().Method1(); } public override string Method2() { return GetStateDependentImplementation().Method2(); } ... } Of course, I can do this (aggregation of base implementation): public RepeaterOfBase: Base // no any overrides, just inheritance { } public class Proxy: Base { private B _b; private RepeaterOfBase _Base; public class Proxy(B b, RepeaterOfBase aBase) { _b = b; _base = aBase; } } ... public Base GetStateDependentImplementation() { if (State == Running) return _b; else return _Base; } ... But instance of Base class is very huge and I have to avoid to have other additional copy in memory. So I have to simplify my code have to "wrap" implementation have to avoid a code duplication have to avoid aggregation of any additional instance of Base class (duplication) Is it possible to reach these goals?

    Read the article

  • how to Clean up(destructor) a dynamic Array of pointers??

    - by Ahmed Sharara
    Is that Destructor is enough or do I have to iterate to delete the new nodes?? #include "stdafx.h" #include<iostream> using namespace std; struct node{ int row; int col; int value; node* next_in_row; node* next_in_col; }; class MultiLinkedListSparseArray { private: char *logfile; node** rowPtr; node** colPtr; // used in constructor node* find_node(node* out); node* ins_node(node* ins,int col); node* in_node(node* ins,node* z); node* get(node* in,int row,int col); bool exist(node* so,int row,int col); //add anything you need public: MultiLinkedListSparseArray(int rows, int cols); ~MultiLinkedListSparseArray(); void setCell(int row, int col, int value); int getCell(int row, int col); void display(); void log(char *s); void dump(); }; MultiLinkedListSparseArray::MultiLinkedListSparseArray(int rows,int cols){ rowPtr=new node* [rows+1]; colPtr=new node* [cols+1]; for(int n=0;n<=rows;n++) rowPtr[n]=NULL; for(int i=0;i<=cols;i++) colPtr[i]=NULL; } MultiLinkedListSparseArray::~MultiLinkedListSparseArray(){ // is that destructor enough?? cout<<"array is deleted"<<endl; delete [] rowPtr; delete [] colPtr; }

    Read the article

  • which situation abstract class i should use

    - by Bharanikumar
    Hi , Am not worked on extream level of oops in my projects , So i have little doubts , In which situation should i use abstract method or classes , Basically i know about abstract class definition and flow, I got details from this URL Doubt is which situation should i use abstract class and methods ,

    Read the article

  • How can I use Object Oriented Javascript to interact with HTML Objects

    - by Steve
    I am very new to object orientated javascript, with experience writing gui's in python and java. I am trying to create html tables that I can place in locations throughout a webpage. Each html table would have two css layouts that control if it is selected or not. I can write all of the interaction if I only have one table. It gets confusing when I have multiple tables. I am wondering how to place these tables throughout a blank webpage and then access the tables individually. I think I am having trouble understanding how inheritance and hierarchy works in javascript/html. NOTE: I am not asking how to make a table. I am trying to dynamically create multiple tables and place them throughout a webpage. Then access their css independently and change it (move them to different locations or change the way the look, independently of the other tables).

    Read the article

  • is there a proper way to handle multiple errors/exceptions?

    - by toPeerOrNotToPeer
    in OO programming, is there some conceptual pattern, ideas, about handling multiple errors? for example, i have a method that performs some checks and should return an error message for each error found ['name is too short', 'name contains invalid unicode sequences', 'name is too long'] now, should i use an array of exceptions (not thrown exceptions)? or something like this is better: class MyExceptionList extends Exception{ public Void addException(Exception e){} public Array getExceptions(){} } any theory behind this argument will be appreciated! (this isn't a request about a specific programming language, but a pure theoretical one) thank you in advance

    Read the article

  • Segmentation fault on instationation of more than 1 object

    - by ECE
    I have a class called "Vertex.hpp" which is as follows: #include <iostream> #include "Edge.hpp" #include <vector> using namespace std; /** A class, instances of which are nodes in an HCTree. */ class Vertex { public: Vertex(char * str){ *name=*str; } vector<Vertex*> adjecency_list; vector<Edge*> edge_weights; char *name; }; #endif When I instantiate an object of type Vector as follows: Vertex *first_read; Vertex *second_read; in.getline(input,256); str=strtok(input," "); first_read->name=str; str=strtok(NULL, " "); second_read->name=str; A segmentation fault occurs when more than 1 object of type Vector is instantiated. Why would this occur if more than 1 object is instantiated, and how can i allow multiple objects to be instantiated?

    Read the article

  • Factory vs instance constructors

    - by Neil N
    I can't think of any reasons why one is better than the other. Compare these two implementations: public class MyClass { public myClass(string fileName) { // some code... } } as opposed to: public class MyClass { private myClass(){} public static Create(string fileName) { // some code... } } There are some places in the .Net framework that use the static method to create instances. At first I was thinking, it registers it's instances to keep track of them, but regular constructors could do the same thing through the use of private static variables. What is the reasoning behind this style?

    Read the article

< Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >