When do Java static initialization blocks execute?

When do Java static initialization blocks execute?

• A. Each time a new instance is created
• B. When the class is loaded by the JVM, before any static methods or fields are accessed
• C. After the first method call
• D. At program termination

Answer: (B)

Static initialization blocks are part of class initialization. They run once, at the moment the JVM initializes the class when it is loaded for use. This happens before you touch any of the class’s static members and before you can create instances of the class. The blocks execute in the order they appear in the source, interleaved with static field initializers, during that first initialization. Because initialization happens only once per class, the blocks won’t run again for every object you create, nor at program termination. The key idea is that class initialization—triggered by the first active use of the class—includes executing these blocks before any static method or field is accessed.

Static initialization blocks are part of class initialization. They run once, at the moment the JVM initializes the class when it is loaded for use. This happens before you touch any of the class’s static members and before you can create instances of the class. The blocks execute in the order they appear in the source, interleaved with static field initializers, during that first initialization. Because initialization happens only once per class, the blocks won’t run again for every object you create, nor at program termination. The key idea is that class initialization—triggered by the first active use of the class—includes executing these blocks before any static method or field is accessed.