Explain the execution flow of static blocks, instance blocks, and methods in Java.

Question

Accepted Answer

Static blocks run once at class loading; instance blocks run for each object; methods execute as called, following the order of execution.

Static blocks are executed when the class is loaded into memory.
Instance blocks are executed when an object of the class is created.
Static block example: static { System.out.println('Static block'); }
Instance block example: { System.out.println('Instance block'); }
Method execution follows the order of method calls in the code.

Accepted Answer

In Java, there are several types of blocks that can be used to define code:

Static blocks: Static blocks are blocks of code that are marked with the static keyword and are executed when the class is first loaded by the JVM. They are typically used to initialize static fields or perform other one-time initialization tasks.
Instance blocks: Instance blocks are blocks of code that are executed when an instance of a class is created. They are typically used to initialize instance fields or perform other tasks that need to be done each time an instance is created.
Constructors: Constructors are special methods that are used to create and initialize objects. They are called when an instance of a class is created, and they can be used to perform any initialization tasks that are needed for the object.

The order of execution for these blocks is as follows:

Static blocks are executed first, in the order in which they appear in the code.
Next, the instance blocks are executed, in the order in which they appear in the code.
Finally, the constructor is called and executed.

Accepted Answer

static block is a set of instructions that is run only once when a class is loaded into memory

Class Hello {

static{

System.out.println("hello static"):

}}

Instance black is similar to method which has no name it can be written inside a class only but ont inside a month

Class A{

Int a,b;

A()

{

a=30; b=40;

System.out.println(a+" "+b);

}

{

a=10; b20;

System.out.println(a+" "+b);

}}

Class B{

public static void main (String [] arg){

A a=new A();

}}

Accepted Answer

A static block is a block of code with a static keyword. In general, these are used to initialize the static members of a class. JVM executes static blocks before the main method at the time loading a class.

A constructor is similar to method and it is invoked at the time creating an object of the class, it is generally used to initialize the instance variables of a class. The constructors have same name as their class and, have no return type.

Instance method

These are the normal methods of a class (non static), you need to invoke them using an object of the class −

Order of execution

When you have all the three in one class, the static blocks are executed first, followed by constructors and then the instance methods.

Accepted Answer

Static Block - a static block is a set of instructions that is run only once when a class is loaded into memory.

Instance Block - it is an element of a class which serves the same two purposes as served by the constructors.

Method Execution Flow -

Write the Java Code.
Compile the Java Code.
Create the . h File.
Write the Native Method Implementation.
Create a Shared Library.
Run the Program.

Anjali

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Explain the execution flow of static blocks, instance blocks, and methods in Java.

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