What is a Static Block in Java and How Does It Work?

Static Block in Java

In Java, one may encounter code blocks enclosed within a static {} syntax, which may be unfamiliar to programmers coming from languages like C . This block of code is known as a static initializer or a "class constructor."

What is a Static Block?

A static block is a code segment that is executed when the class is loaded into memory. Its purpose is to initialize class-wide data or perform any necessary actions before any instance of the class is created.

Unlike instance initializers, which are executed when an object is instantiated, static blocks are executed only once during class loading. They are typically used for tasks such as:

• Initializing static variables
• Registering event listeners
• Loading resources
• Performing system-level configurations

Example:

public class MyClass {

    static {
        // Code to initialize class-wide data
        System.out.println("Static initializer executed");
    }

    public static void main(String[] args) {
        // Code to create instances and execute instance initializers
    }
}

In this example, the static block will print "Static initializer executed" when the MyClass class is loaded.

Note:

• Static blocks are executed before any instance of the class is created, including the main method.
• Multiple static blocks can be defined within a class, and they will be executed in the order they are written.
• Static blocks are final and cannot be overridden by subclasses.

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