Jan 23, 2019

Core Java Concepts for Beginners

Java has been around since 1995, and it's not poised to leave anytime soon. Not only is Java one of the most popular programming languages, it's also great for beginners. You do need to write a lot of the code very explicitly, which is helpful for anyone just starting out. There's a strong community behind it, providing many resources. Perhaps most exciting of all is the huge market interested in hiring programmers with all levels of experience in Java coding.

No matter if you're thinking of taking a course like Intro to Programming or you want to begin learning on your own, understanding core Java concepts is essential. To help get you started, here's a list of some of the must-know core Java concepts for beginners.

Development Cycle for Building Java Software

When you create programs in Java, you're writing code into Java source files, which are files of text with the "".java"" extension. All of the files are then placed into Java class files using a Java compiler. They're assembled into ZIP archives also known as JAR files. Those files then go to the Java Virtual Machine to begin the building process.


Variables are fundamental to programs in any language. By definition, a variable has a life cycle that stretches from beginning to end. It can be stored in external storage, have its value changed, and be used in computation. For example, if you're trying to compute the area of a circle, you could store the circle's radius in a variable and use it in your code to calculate the area.


Every variable in Java programs has a type. That could be something as simple as a number or something more complex, such as user-defined classes. There are three main types:

  • Primitive variables include characters, single 8-bit values known as bytes, 32-bit integers or ints, floats or single-precision floating point numbers, 64-bit integers known as longs and double-precision floating point numbers known as doubles.
  • Built-in Java classes allow you to manipulate and store data within Java.
  • User-defined classes are more complex blueprints for concepts within the program.


Classes are like the architectural plans for concepts. They includes methods, variables, and instances like objects and constructors.


Packages are units of organization. Classes and related classes are often grouped together within a package. The package is then named and organized in a hierarchical scheme and stored in a folder.

This is just a brief primer on core Java concepts. There are several additional concepts that you should familiarize yourself with before moving on to more advanced Java usage. If you want a more formal education in Java, programming, data science, or another field, consider pursuing a Udacity Nanodegree program to kickstart your education and pave the way to a bright future.