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Do constructors initialize fields?
Instance variables can be initialized in constructors, where error handling or other logic can be used. To provide the same capability for class variables, the Java programming language includes static initialization blocks. It is only necessary that they be declared and initialized before they are used.
How do you initialize a field?
The way to initialize class fields is with something called a static initializer. A static initializer is the keyword static followed by code in curly braces. You declare a class field much as you would declare a local variable. The chief difference is that field declarations do not belong to any method.
What does it mean to initialize a field?
In computer programming, initialization (or initialisation) is the assignment of an initial value for a data object or variable. Initialization is done either by statically embedding the value at compile time, or else by assignment at run time.
Do constructors need return?
No, constructor does not return any value. While declaring a constructor you will not have anything like return type. In general, Constructor is implicitly called at the time of instantiation. And it is not a method, its sole purpose is to initialize the instance variables.
What is the return type of constructors * 1 point?
1. What is the return type of Constructors? Explanation: Constructors does not have any return type, not even void.
How are field initializers different from base class constructor?
For your simple example, it is simply a matter of style. There are subtle differences when inheritance is involved. For instance field initializers, the order of execution is derived class field initializers, base class field initializers, base class constructor, derived class constructor.
When to use self assignment or initialization in constructor?
Apart from other answers, I would like mention that constructor initialization only for initialize member variables. if we initialize a and b inside constructor it would be self assignment. First is initialization, using an initializer list and the second is default construction and then assignment.
Do you have to intialize a reference in a constructor?
Note: It is mandatory that a reference or a const member must be intialized in a constructor initialization list. They cannot be ‘assigned’ in the body of the constructor. Apart from other answers, I would like mention that constructor initialization only for initialize member variables.
Can a user defined type be initialized without a default constructor?
However, user defined types without a (n explicitly defined or generated) default constructor can’t be initialized this way, so a compiler error is produced. The same is true for const and reference fields – these can only be initialized explicitly in the member initializer list.