• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Tim Cooke
  • Devaka Cooray
  • Ron McLeod
  • Jeanne Boyarsky
Sheriffs:
  • Liutauras Vilda
  • paul wheaton
  • Junilu Lacar
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Piet Souris
  • Carey Brown
  • Tim Holloway
Bartenders:
  • Martijn Verburg
  • Frits Walraven
  • Himai Minh

abstract class

 
Greenhorn
Posts: 6
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator


abstract class cannot be instantiated but why abstract class can have constructors ???
 
Rancher
Posts: 175
Clojure Java Linux
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

gaurav gupta sitm wrote:abstract class cannot be instantiated but why abstract class can have constructors ???


To ensure that all children of the abstract class are initialized at least to the extent provided by that constructor!
 
Ranch Hand
Posts: 300
Eclipse IDE Firefox Browser Linux
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Abstract class is for a purpose its an incomplete class but provide basic functionality and when some class extends and completes it it require super class initialization, so having constructor in abstract class is perfectly legal. you may find my blog post about abstraction in java interesting.
 
Greenhorn
Posts: 12
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I can surely say that "Every Class has a Constructor". Even in abstract classes.
 
Ashoka Jayasekara
Greenhorn
Posts: 12
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I can surely say that "Every Class has a Constructor". Even in abstract classes.
 
author
Posts: 23928
142
jQuery Eclipse IDE Firefox Browser VI Editor C++ Chrome Java Linux Windows
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Or in other words, just because a class can't be instantiated directly, doesn't mean it can't be instantiated. When it is instantiated, the constructor is responsible for initialing and configuring the components of that class.

Henry
 
Ranch Hand
Posts: 1376
Eclipse IDE Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
abstract class can have constructor as mentioned above because every class have constructor.

How constructor of abstract class can be helpful to you -> you can set up instance variable defined in abstract class in these constructor




Hope this helps
 
It's feeding time! Give me the food you were going to give to this tiny ad:
the value of filler advertising in 2021
https://coderanch.com/t/730886/filler-advertising
reply
    Bookmark Topic Watch Topic
  • New Topic