Can we initialize variable in constructor?

Yes, you can also initialize these values using the constructor.

Why do we initialize variable in constructor?

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.

Why static variable is initialized in constructor?

A static variable can be accessed without an object, therefore the variable shouldn’t be static if you need to initialize in the constructor. It makes no sense to “initialize” a static member in a constructor. It will get reinitialized every time you create a new instance.

Why Cannot a variable we initialize inside a class?

The main reason is that initialization applies to an object, or an instance, and in the declaration in the class there is no object or instance; you don’t have that until you start constructing.

How do you initialize a constructor?

There are two ways to initialize a class object:

1. Using a parenthesized expression list. The compiler calls the constructor of the class using this list as the constructor’s argument list.
2. Using a single initialization value and the = operator.

How do you initialize an instance variable in a constructor?

Instance Variables and Constructors. Instance variables are always prefixed with the reserved word self. They are typically introduced and initialized in a constructor method named __init__. The constructor method always expects at least one argument, self.

Should I initialize in constructor?

A class object with a constructor must be explicitly initialized or have a default constructor. Except for aggregate initialization, explicit initialization using a constructor is the only way to initialize non-static constant and reference class members.

Where should variables be initialized?

Variables are explicitly initialized if they are assigned a value in the declaration statement. Implicit initialization occurs when variables are assigned a value during processing.

Do static variables need to be initialized?

Static variables are initialized only once , at the start of the execution. These variables will be initialized first, before the initialization of any instance variables. A single copy to be shared by all instances of the class. A static variable can be accessed directly by the class name and doesn’t need any object.

Can final field be initialized in constructor?

final means the variable can only be assigned once (in the constructor). static means it’s a class instance.

Why We Can not initialize members of structure at the time of declaration?

Structure members cannot be initialized with declaration. For example the following C program fails in compilation. }; The reason for above error is simple, when a datatype is declared, no memory is allocated for it.

Can you initialize variables in a class?

To initialize a class member variable, put the initialization code in a static initialization block, as the following section shows. To initialize an instance member variable, put the initialization code in a constructor.