Must learn classes for Java! [closed]

Question

What would you consider the key/important classes for all java beginners to learn to grasp the funadamentals of the languag?

String, Array, Scanner, File, PrintWriter etc ?

Answer 1

Aside from the very basic things like primitive types, the following come to mind. This isn't complete, but these are the things that I find myself using most frequently

• Input/output with files and command line: BufferedReader/BufferedWriter/Scanner, etc.
• Java Collections Framework: All the List, Set, and Map classes
• Thread/Runnable: Beyond what the classes do, knowledge about deadlock, thread safety, and synchronization are all key.

Answer 2

A good starting point is the trail in the Java Tutorials on the Essential Classes. From there you'll definitely branch off in different directions depending on what kind of programming you do.