spot7.org logo
Home PHP C# C++ Android Java Javascript Python IOS SQL HTML Categories

Scala Child Class Constructor is not being called from Java Parent Class


Constructors in Scala work differently than Java. In particular, they are not a def with the same name as the class. There are various places you can read about it.

In any case, if you really need alternate constructors, they look like so:

class C(name: String) {
  def this(i: Int) = this(i.toString)
}

(The reason is that forgetting to properly initialize things in alternate constructors is a significant source of bugs and extra boilerplate. By forcing everything to go through a single main constructor, syntax is simpler when you only need one constructor, and initialization bugs are less likely.)


Categories : Java

Related to : Scala Child Class Constructor is not being called from Java Parent Class
Class Inheritance, using Child Class to set up Parent Class
It's good practice to call the super-init-method, so I would suggest: class Character(): 'Common base class for all characters' def __init__(self, attack, defence, strength): self.attack = attack self.defence = defence self.strength = strength class Enemy(Character): 'Enemy Class' def __init__(self): Character.__init__(self, attack=random.randint(

Categories : Python
Call method from a parent class and use child class properties
Firstly, I'd suggest avoiding using public fields - use properties if you want to make state public. (You're asking for a property in your reflection call, but your derived class declares a field...) At that point, you can make FullName an abstract property in the base class, and allow each derived class to implement it however they want - but you can still call it from the base class. On the ot

Categories : C#
C++: Problems creating a child class within a parent class
I don't think it is possible for a parent class to have an instance of a child class. You can use a child class pointers instead of child class objects for your purpose. Define child classes in separate header files. Add forward declarations of child classes in parent class header file. Use child class pointers instead of child class objects. Initialize child class pointer members of parent cl

Categories : C++
I am Always getting the Instance of Parent Class.But i need a child one
The return type of the getInstance(int xmlTypeId) is WSType which is the parent. You can simply cast it to WSStringType2 because WSStringType2 extends WSStringType and WSStringType extends WSType WSType wt = WSType.getInstance(STRING); WSStringType2 wt2 = null; if (t instanceof WSStringType2) { wt2 = (WSStringType2) wt; }

Categories : Java
I don't understand the call to the parent class from within the class in this JAVA class
Your DownloadHandler class has a static void main method, which is the single point of entry when executing command-line programs. That method is not a constructor. What it does is initialize a new instance of DownloadHandler and invoking an instance method on that object by passing the given String argument. Not sure what's the usage there. In order for your initialization to compile, you

Categories : Java
Recently Add
Redirecting the output directory of 'mvn package' or 'mvn compile' command
No suitable constructor found for ProductoExtranjero
java Composite design pattern(Directory &File)
Java JTree's ui refresh after removing node from parent
First REST Spring application
How to cancel Indexing of a Solr document using Update Request Processor
PowerMock - Mock a Singleton with a Private Constructor
Calling a Postgres stored function SQL error
Where to store Morphlines Java custom command class?
Generic repository using map
How can I scroll a ScrolledComposited in Eclipse SWT Design view?
2 Frames/layout in 1 Activity
Writing a switch differently
Next button opens another activity when its reaches the array limit
Is EclipseLink MOXy capable of applying JSR-303 Bean Validation when unmarshalling XML to object?
Why my jdk can't work,and before the java_home, there is a space that is not from me
How to add List of objects in a Map
How to make notepad++ function like regular notepad in cmd?
Cell renderer and the lost focus
how can I implement iterable for LinkedList>
Disable Androids image-crunch in eclipse (run as) builds
java 8 lambda myMap.stream().count() != myMap.size() after merging myMap
Issue with Calendar calculation that spans 2 calendar years
JSF 2.0 Spring bean injection
Java Regex ReplaceAll with grouping
Getting any word and last word using sed
Clicking on link on JEditorPane throws IOException
printing out difference of two arrays
Spring Bean Alias in JavaConfig
Using Factory Method to Create Generics
© Copyright 2017 spot7.org Publishing Limited. All rights reserved.