Is this a static method? "static {...}"

Question

I was going through an exercise in Head First Java. It has the following code :

static {
System.out.println("Super constructor block");
}

i dont get the static modifier that is before the curly braces. What is it called? I know static variables etc. I tried searching online but couldn't get an answer. Thanks.

this is a static block – Thusitha Thilina Dayaratne May 24 '15 at 12:03 — Thusitha Thilina Dayaratne, May 24 '15 at 12:03

score 5 · Answer 1 · edited May 24 '15 at 12:06

5

It is called a static initialization block. See https://docs.oracle.com/javase/tutorial/java/javaOO/initial.html:

A static initialization block is a normal block of code enclosed in braces, { }, and preceded by the static keyword.

It executes once the class is loaded by the JVM.

edited May 24 '15 at 12:06

T.J. Crowder

1,031,962
187
1,923
1,875

answered May 24 '15 at 12:05

M A

71,713
13
134
174

Asif Mujteba · Answer 2 · 2015-05-24T12:29:15.223

1

This is a static block not static method.

static blocks are different than static methods.
static blocks need not be called and are automatically executed. static blocks insure that they are only called once, When the class gets loaded.
static blocks can be written anywhere in the class, before execution compiler will combine all static blocks and execute at once on class load.
You can only initialize/access static variables/methods in a static block. Which means you cannot access non-static variables inside a static block, same as with a static method.
As static methods can be called more than once unlike blocks, which makes methods reusable, which is downside of blocks.
Static blocks are normally used to initialise static variables or do other calculations which are needed before a class instance is created or any static field is accessed..

For more information, refer to these links:

JavaCode.in

Oracle Docs

edited May 24 '15 at 12:29

answered May 24 '15 at 12:05

Asif Mujteba

4,596
2
22
38

Your welcome.. no upvotes :( – Asif Mujteba May 24 '15 at 12:25
static variables can be accessed outside static blocks.. – karthik manchala May 24 '15 at 12:27
check your 4th point – karthik manchala May 24 '15 at 12:28
it just says we can access only static variables in the block... meaning non-static variables cannot be access inside the block!!! – Asif Mujteba May 24 '15 at 12:31
however i have added further clarification! – Asif Mujteba May 24 '15 at 12:32

score 1 · Answer 3 · answered May 24 '15 at 12:08

1

This is called "static block". It is executed only once: the first time you make an object of that class or the first time you access a static member of that class (even if you never make an object of that class). See this link

answered May 24 '15 at 12:08

Mohammed

43
7

Is this a static method? "static {...}"

3 Answers3