What are Java code blocks? What are the types?

        In Java , a code block is a collection of Java statements enclosed in a pair of braces {}. Code blocks are used to define pieces of code that are executed within a specific scope. Java code blocks are divided into the following types:

　　1. Code block within the method:

　　This is the most common type of code blocks, they are located inside Java methods. The code block within a method is used to define local variables within the method and perform operations within the method. For example:

public void someMethod() {
    int x = 10; // 方法内的代码块
    // ...
}

　　2.Instance Initialization Block:

　　An initialization block is a non-static block of code in a class that is used to perform initialization operations when creating objects of the class. The initialization block is executed every time an object is created. For example:

public class MyClass {
    {
        // 初始化块
        // 在每次创建对象时执行
    }
}

　　3. Static Initialization Block:

　　A static initialization block is a static code block in a class that is used to perform initialization operations only once when the class is loaded. Usually used to initialize static variables or perform static operations. For example:

public class MyClass {
    static {
        // 静态初始化块
        // 在类加载时执行一次
    }
}

　　4. Synchronized Block:

　　Synchronized blocks are used to control access to shared resources in a multithreaded environment. It is defined using the synchronized keyword to ensure that only one thread can execute the code inside the synchronized block at the same time. For example:

public class MyClass {
    static {
        // 静态初始化块
        // 在类加载时执行一次
    }
}

　　These code block types allow code to be executed at different scopes and timings to meet different needs. According to the needs, we can choose the appropriate code block type to organize and control the execution of the code.