Java Fundamentals Explained: Platform Independence, JDK, JVM, and Core Concepts

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Java is a high-level, object-oriented programming language originally developed at Sun Microsystems and now maintained by Oracle, built around the principle of Write Once, Run Anywhere. This is achieved by compiling Java code into bytecode that any Java Virtual Machine (JVM) can execute, regardless of the underlying operating system. The Java ecosystem distinguishes three key components: the JVM, which runs bytecode; the JRE, which bundles the JVM with necessary libraries; and the JDK, which adds development tools on top of the JRE. A basic Java program requires a class with a main() method as the entry point, from which the JVM begins execution. Java supports eight primitive data types, including int, double, char, and boolean, alongside reference types such as String that point to objects in memory.

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ProgrammingDEV Community ·

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