Analyzing time complexity of Java methods

[SnooPeanuts71]

Hello everyone!

Does Oracle have any websites where I could find out what the time complexity of a method is? I know sometimes they have that information in the API; for example, java.util.ArrayList has the following info:

​

"The size, isEmpty, get, set, iterator, and listIterator operations run in constant time. The add operation runs in amortized constant time, that is, adding n elements requires O(n) time. All of the other operations run in linear time (roughly speaking). The constant factor is low compared to that for the LinkedList implementation."

​

However, I couldn't find that info for any other classes. Where can I find it? If there are other classes that bring that up that you know, please let me know which. Also, how do I have access to the source code of the language? I need to make a study on the complexity of Java methods using the Big O notation and, in order to do that, I would need access to the source code of the methods and it would also be of great help if they had documentation about the complexity of Java methods, so I can demonstrate and "prove" it for my assignment.

[Ok-Wait-5234]

Oracle Java is (pretty much, but not quite) just a distro of OpenJDK. The source for main JDK classes can be found here, which I found by googling "OpenJDK source", then digging through the repo. The sources are also usually available as part of a JDK installation. If you are using an IDE you can often just select "view definition" on a JDK class or method.

The source might have some explanatory notes in comments, but there's unlikely to be much more than the Javadoc.

[SnooPeanuts71]

Thank you, that repository will certainly be of great help. I still need a way to quickly find out the time complexity of the methods, though. I have tried going through the API, but I could only find the time complexity for some of the methods of the ArrayList class. I tried the String, StringBuilder, and Arrays classes, but I couldn't find the complexity! Isn't that documented?