Java was initially created at Sun Microsystems by a group of engineers under the leadership of James Gosling. The language made its first appearance in 1995, aiming to provide a platform-independent programming environment that could work across different types of systems.

Currently, Java is maintained and developed by Oracle Corporation. Oracle acquired Sun Microsystems in 2010, and with that acquisition, it took over responsibility for the ongoing support, updates, and evolution of the Java platform.

Java stands out because it is a high-level language that is compiled and strongly typed, with full support for object-oriented programming. Its major benefits include being able to run on any system with a compatible Java Virtual Machine, a syntax that resembles C, built-in memory management through garbage collection, a vast and useful runtime library, corporate support from Oracle, and strong backing from the open-source developer community.

Calling Java “object-oriented” means that it is built around the idea of using classes and objects. These constructs help programmers represent both real-world and abstract entities within the code. Java supports the fundamental principles of object-oriented programming such as encapsulation, inheritance, and polymorphism. Objects in Java are created based on class definitions, where a class acts like a template describing the state and behavior of the object. The state is represented through fields (variables), and the behavior is defined using methods.

Although Java uses an object-oriented approach, it is not completely object-oriented. This is because it also includes primitive data types, which are not objects. These primitive types are:

boolean: size is not fixed (depends on the JVM), used to represent true or false values
byte: 8-bit signed integer
short: 16-bit signed integer
char: 16-bit unsigned value representing a Unicode character
int: 32-bit signed integer
long: 64-bit signed integer
float: 32-bit floating point number
double: 64-bit floating point number

The Java Language Specification defines the syntax and rules that Java code must follow. It sets the standards for both how the code should be written and what it should mean. Syntax errors are like grammatical mistakes in a sentence—for example, “He go to school” instead of “He goes to school.”

On the other hand, semantic errors happen when a sentence is grammatically correct but logically meaningless, like saying, “My refrigerator danced across the highway.” In Java, a program might compile correctly but behave incorrectly if there's a semantic mistake.

JAVA

Learning Path

Introduction