How many classes are there in Java standard edition?

Question

I am curious how many classes are there in Java standard library. Perhaps someone knows an approximate number?

Answer 1

I see 3793 counting interfaces and abstract classes, as well as private classes.

Answer 2

Calculating classes and subclasses is a cumbersome task, but you can know the number of files. 4240 total files in Jdk 8. Click here for the list of all files.

Answer 3

For Java SE 9 , according to the API doc 6005 including abstract and interfaces.

For Java SE 10, according to the API doc 6002 including abstract and interfaces.

https://docs.oracle.com/javase/10/docs/api/allclasses-noframe.html

Method : view source, and count "<li>" html tag with notepad++.

For Java SE 11, according to the API doc 4411 including abstract and interfaces.

For Java SE 12, according to the API doc 4433 including abstract and interfaces.

https://docs.oracle.com/en/java/javase/12/docs/api/allclasses-index.html

Method : view source, and count "colFirst" css class with notepad++

Answer 4

I'm also curious about this topic. I found this:

(source: Java 8 Pocket Guide book by Robert Liguori, Patricia Liguori)

Answer 5

I see 3762 within Java 8 as following

All Classes ( Outer as well as Inner ) , Enums and Interfaces -  3762
All except Inner Classes                                      -  3462
Only Classes ( Outer + Inner + Abstract + Enum )              -  2963
Interfaces                                                    -  799
Enum                                                          -  93  

Moreover , Here is the list of classes / interfaces introduced with each version - http://qr.ae/Q2baW

Answer 6

• Java 1.0.2 : 250 classes
• Java 1.1 : 500 classes
• Java 2 (version 1.2-1.4) : 2300 classes
• Java 5.0 (version 1.5) : 3500 classes

Source : Head First 2nd edition, Chapter 1, p. 4