8 Answers. An empty constructor is needed to create a new instance via reflection by your persistence framework . If you don’t provide any additional constructors with arguments for the class, you don’t need to provide an empty constructor because you get one per default.
Read moreCan a default constructor be empty?
Providing an empty default constructor( private ) is necessary in those cases when you don’t want an object of the class in the whole program . For e.g. the class given below will have a compiler generated default empty constructor as a public member . As a result, you can make an object of such a class.
Read moreDoes Java need an empty constructor?
Every tutorial I saw said : every entity needs an empty constructor . But Java always give you a default invisible empty constructor (if you don’t redefine one). … But Java always gives you this empty constructor when you don’t redefine it (write an other one with parameters).
Read moreHow do I call a no-arg constructor?
The syntax to call a superclass constructor is as follows: Syntax: super() , or super(Parameter_list); The statement super() calls the no-argument constructor of its superclass and the super(argument) invokes the superclass constructor where the argument must match.
Read moreWhat makes a constructor overloaded?
What is Constructor overloading? Constructors with the same name but different signature are called overloaded constructors. They may have different numbers of arguments, different sequences of arguments, or different types of arguments.
Read moreWhat is a no-arg constructor in Java?
No-Arg Constructor – a constructor that does not accept any arguments . Parameterized constructor – a constructor that accepts arguments. Default Constructor – a constructor that is automatically created by the Java compiler if it is not explicitly defined.
Read moreWhy do we need no-arg constructor?
The arguments of a constructor can only be found by type, not by name, so there is no way for the framework to reliably match properties to constructor args . Therefore, they require a no-arg constructor to create the object, then can use the setter methods to initialise the data.
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