accessor

Calling superclass from a subclass constructor in Java

由 蹲街弑〆低调 提交于 2019-11-27 01:59:31
I am trying to create a constructor that takes a field as a parameter, then puts it in a field that is stored in a superclass. Here is the code I am using public crisps(String flavour, int quantity) { this.flavour = super.getFlavour(); this.quantity = quantity; } In the superclass I have initialised the field with private String flavour; and I have an accessor method public String getFlavour() { return flavour; } I am getting an error " flavour has private access in the superclass ", but I believe this shouldn't matter as I am calling the accessor method that returns it to the field? What you

Difference between pure and impure function?

由 好久不见. 提交于 2019-11-27 01:52:59
问题 I assumed that pure functions must always have a return type (i.e., must not be void ) and must have the same output regardless of the state of the object and that Impure functions change the state of the object or print the state of the object. But the textbook I use states that: An accessor usually contains a return statement, but a method that prints information about an objects state may also be classified as an accessor. I'm confused. Which one is correct? EDIT A bit of clarification,The

Valid use of accessors in init and dealloc methods?

由 我的未来我决定 提交于 2019-11-27 00:33:16
I've heard now from several sources (stackoverflow.com, cocoa-dev, the documentation, blogs, etc) that it is "wrong" to use accessors and settings (foo, setFoo:) in your init and dealloc methods. I understand that there is there is a remote possibility of confusing other objects that are observing the property if you do so. (a simple example is given here ) However, I have to say that I don't agree with this practice for the following reason: The new Objective-C runtime (the one on the iPhone and the 64-bit runtime in 10.5) allows you to declare properties without declaring a corresponding

Accessing object property as string and setting its value

由 荒凉一梦 提交于 2019-11-27 00:06:33
问题 I have an instance of the Account class. Each account object has an owner, reference, etc. One way I can access an accounts properties is through accessors like account.Reference; but I would like to be able to access it using dynamic string selectors like: account["PropertyName"]; just like in JavaScript. So I would have account["Reference"] which would return the value, but I also would like to be able to assign a new value after that like: account["Reference"] = "124ds4EE2s"; I've noticed

Java - Using Accessor and Mutator methods

由 孤者浪人 提交于 2019-11-26 22:42:47
I am working on a homework assignment. I am confused on how it should be done. The question is: Create a class called IDCard that contains a person's name, ID number, and the name of a file containing the person's photogrpah. Write accessor and mutator methods for each of these fields. Add the following two overloaded constructors to the class: public IDCard() public IDCard(String n, int ID, String filename) Test your program by creating different ojbects using these two constructors and printing out their values on the console using the accessor and mutator methods. I have re-written this so

public variables vs private variables with accessors

由 删除回忆录丶 提交于 2019-11-26 21:08:40
问题 Has anyone else seen people do this: private string _name; public string Name{ get{ return _name; } set{ _name = value;}} I understand using accessors if you are going to exercise some sort of control over how it gets set or perform some sort of function on it when there is a get. But if you are just going to do this, why not just make the variable public to begin with? Am I missing something? 回答1: If you make the member a public field, then you can't later refactor it into a property without

Should accessors return values or constant references?

由 寵の児 提交于 2019-11-26 20:16:27
问题 Suppose I have a class Foo with a std::string member str . What should get_str return? std::string Foo::get_str() const { return str; } or const std::string& Foo::get_str() const { return str; } What is more idiomatic in C++? 回答1: The short answer is: it depends :-) From the performance point of view returning a reference is (usually) better: you save the creation of a new std::string object. (In this case, the creation is costly enough and the size of the object is high enough to justify

static/Shared in VB.NET and C# visibility

由 喜欢而已 提交于 2019-11-26 17:03:44
问题 I have faced with a situation in VB.NET and C# (.NET2) with the visibility of the static/shared members. It seems to me a little strange in VB.NET: public class A { private static A instance; public static A Instance { get { return instance; } } public string Name { get { } } } usage : A.Instance.Name // ONLY Name is "visible" VB.NET: Public Class A Private Shared _instance As A Public Shared ReadOnly Property Instance() As A Get Return _instance End Get End Property Public ReadOnly Property

Why are symbols in Ruby not thought of as a type of variable?

由 穿精又带淫゛_ 提交于 2019-11-26 11:30:29
问题 New to programming and to Ruby, and I hope this question about symbols is in line. I understand that symbols in Ruby (e.g., :book , :price ) are useful particularly as hash keys, and for all-around doing a lightweight, specific subset of the things that strings can do. However, I am confused about symbols in one respect. Specifically, when they\'re used in the attr_accessor types of methods, it appears that they are behaving more like a variable. E.g., attr_reader :book, :price . If true that

Valid use of accessors in init and dealloc methods?

由 自闭症网瘾萝莉.ら 提交于 2019-11-26 09:26:11
问题 I\'ve heard now from several sources (stackoverflow.com, cocoa-dev, the documentation, blogs, etc) that it is \"wrong\" to use accessors and settings (foo, setFoo:) in your init and dealloc methods. I understand that there is there is a remote possibility of confusing other objects that are observing the property if you do so. (a simple example is given here) However, I have to say that I don\'t agree with this practice for the following reason: The new Objective-C runtime (the one on the
订阅 accessor