Java Introduction
Contents
Java
Is Platform Independent
Common compilers translate source code into platform-specific code (specific to the processor on that computer (ARM, x86, x64, MIPS, etc). However this can make programs hard to be portable between different platforms and systems.
The Java language addresses this issue by implementing intermediate 'byte code' - Where the source code (.java
) is compiled into Java byte-code.
The Java Virtual Machine, installed on the target system, then interprets the byte-code and translates it into its own platform-specific code.
Has automatic memory management
Automated Garbage Collection (GC) is implemented within Java, so that you don't have to manually clean up the memory.
Is not-as-low-level-as-other-languages
There are a few things we cannot do, like garbage-collection of memory.
Is multithreaded
...out of the box
...when implemeneted
Static Methods (Class methods)
Class methods are functions that belong to the class, rather than an instance of that class.
Initialising classes
To initialise a class, we must prepend the new
keyword
For example,
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Access Modifiers
public
- Anyprotected
- Any subclass in any package-
(default) Any subclass within that packageprivate
- Only that class