Should be : import *.B public class A extends B { private A (java.lang.String[] args) { super(args); } } solved Java: How can I inherit a constructor from a superclass with “java.lang.String[] args” as a parameter?
Because you are passing the classes by const reference, I assume you want to copy them. For that you will need additional virtual member function clone which will return a pointer to a dynamically allocated copy of the object. class func { … virtual func* clone() const; … }; class polynom: public func { … … Read more
C++, Why can’t I put the definition of class constructor with parameters-initialize list outside the class declaration [closed] solved C++, Why can’t I put the definition of class constructor with parameters-initialize list outside the class declaration [closed]
T *t = new T; // ^^^^^ This is a declaration of t of type T*. It is being initialized by the expression after the =. The entire new T part is the new-expression in this initializer. The new-expression causes memory to be allocated for an object of type T and then that object is … Read more
I think you mean this.stack = new double[default_capacity]; and also this.stack = new double[capacity]; 4 solved Type mismatch: cannot convert from double to double[]
A (int n = 0) : m_n(n) {} // ^^^^^^^^^^ It is called the member-initialization-list. In the definition of a constructor of a class, it specifies initializers for direct and virtual base subobjects and non-static data members. For example in: A (int n = 0) : m_n(n) {} Here, your constructor of the A class … Read more
Make some adjustments: Person p1 = new Person(cousebookname); Pass the variable name only. public Person(String name) { courseName = name; } Make the constructor public. solved How to pass parameter to constructor [closed]
Figured it out: public class MyClass { public MyClass() { } public MyClass(MyClass baseInstance) { var fields = typeof(MapObject).GetFields(); foreach (var field in fields) field.SetValue(this, field.GetValue(baseInstance)); var props = typeof(BaseItems).GetProperties(); foreach (var prop in props) if (prop.CanWrite) prop.SetValue(this, prop.GetValue(baseInstance)); } } … lets you do this: public static MyClass MyClass2 => new MyClass(MyClass1) { Property1 … Read more
You can define a natural ordering for your class IceCream by implementing the Comparator interface. public class IceCream implements Comparator{ // … final String name; final Date date; public Icecream(String name, Date date){ this.name = name; this.date = date; } public int compare(Object o1, Object o2) { return ((IceCream)o1).date.compareTo(((IceCream)o2).date); } } 3 solved sorting (constructor) … Read more
First of all, the code you posted is not valid Java. It is important that you post working code, otherwise we can’t be sure about what you are asking. Does the statement super(1,2,3) in the class B create a private fields same as the private fields in the class A? Or is it illegal to … Read more
Private variables are there to help with the work behind the scenes in a class, work that the creator doesn’t want you interfering in. Just because you can’t see or access the private variables, it doesn’t mean the compiler’s just going to throw them away. Perhaps it will make more sense to you in this … Read more
Step one, make a constructor that takes a String and an int. Parrot(String name, int age) { this.age = age; this.name = name; } Step two, call that constructor with a hardcoded default name and an age provided. Use this. Like Parrot(int i) { this(“Polly”, i); } solved How to call a constructor within a … Read more
The constructor initializes the variables(fields) of a class. The default constructor initializes to default values. Example, string to “”, integers to zero, doubles to 0.0, boolean to false an so on. When you create a constructor you’re customizing the variables initialization. 3 solved What Exactly Does A Constructor Do? (C++) [closed]
java.util.Date, like a lot of other classes in the JDK, overrides toString(), which allows you to control the string representation of your objects. You can, of course, do this for your own classes too. 1 solved How new Java.util.Date() works while other classes return just reference?
First of all, toString method comes from object class, don’t try to make multiple of those methods or anything like that, have everything in one method. As to your problem, you can make a variable String description for your class, and initialize it in constructor and then in toString just return that variable. You can … Read more