When is static initializer executed

The advantage of private static methods is that they can be reused later if you need to reinitialize the class variable. Therefore, this approach can be used to share a block of code between multiple constructors. Here is an example:. To prevent the static initialization order problem, use the Construct On First Use Idiom, described below.

Suppose that List is the name of some class. Then function f declares a local List object called x :. Instance initialization block will only be called when the constructor of the class is called for creating an object of class A.

The bottom line is, despite their differences at the language level, static initializer blocks and companion object initializers are the same at the bytecode level. Only after that will the JVM execute the initializer logic. In Java, to initialize static components of a class, we can use static initializer blocks :.

They execute before the instance block whereas instance block executes after the static blocks. Community Bot 1 1 1 silver badge. Petr Mensik Petr Mensik Instance intialization blocks come into play during the constructor, after super is executed.

First - run child class only comment the extend clause to see the simple flow. Static init blocks are executed at the time of class loading. In the class hierarchy the order for execution of static init blocks will start from top level class.

In a class the order for the execution of static block is from top to bottom. Above rule apply regardless of where the static block is present within the class. Instance init blocks will be executed after the call to the super ; in the constructor. Always super ; is the very first statement in a default constructor. In your code when you create a Child object: The default constructor of the Child class get executed. It will call to the super ; constructor. Then the super class constructor is executed.

The Parent class will execute its super ; call. After that the instance init blocks in the Parent class are executed. From top to bottom. Then the code within the constructor is executed if any. Then it will return to the Child class and execute the Child class instance init blocks. Finally the code in the child constructor get executed If exists. Andre Hofmeister 2, 11 11 gold badges 43 43 silver badges 70 70 bronze badges. Sayanthan Mahendran Sayanthan Mahendran 1 1 silver badge 3 3 bronze badges.

Your second bullet point is correct, and your third bullet point contradicts it, so it is therefore incorrect. Instance Initialization Blocks: Runs every time when the instance of the class is created. CKR Loading the chld class requires loading its parents. It wouldn't make sense not to initialize the parent first. Mihai Savin Mihai Savin 53 5 5 bronze badges. JVM looks for a class which has public static void main String args[] so that it can load that class.

No specification data found for javascript. No compatibility data found for javascript. No specification found No specification data found for javascript. Class static initialization blocks v8. Logical nullish assignment?? Object initializer Operator precedence Optional chaining?. Please Subscribe Please subscribe to our social media channels for daily updates. All Rights Reserved. An instance initialization block can not only access static variables and static methods but also instance variables and instance methods of the class.