Go vs Java: Differences and Similarities Compared

Go vs Java Summary

Java is older, object-oriented, and has a larger library and community. Go (or Golang) is newer, multi-paradigm, and better supports concurrency. While Go runs faster than Java, Java has more features and better support. They are both used for server-side programs.

Both Go and Java are used around the world, and they compete directly for control of server-side web applications. But it also competes on other fronts, like your time spent learning a new language.

In a classic battle of old vs. new, how do these two contenders stack up against each other? Let’s cover some background on both, then contrast Go vs Java.

Java Programming

Java has been around awhile. It’s statically typed, compiled (kind of), and general-purpose. Java programming language was originally developed by Sun Microsystems and was released back in 1995. It’s been said that Java is the most widely-used language of all time. 

Java was once the go-to language for server-side applications but has since lost that title. Though no longer regarded the king, it’s still used around the world with thousands of different applications.

But just because it’s getting on in age for server-side apps, that doesn’t mean it isn’t still relevant. It’s been used on a huge number of platforms; from old legacy software on servers, to modern applications in data science and machine learning.

Because it’s so widely adopted, there are a ton of pre-built modules and code already floating around to use. This makes coding a lot easier with Java because, chances are, the integration you’re looking for has already been made. 

Java runs on a virtual machine, but that’s its only real dependency. It’s designed to boot up anywhere there’s processing power; from your microwave to server banks. It’s kind of a compiled language, with the virtual machine breaking the code down into bytecode and then compiling it very quickly at runtime. 

Java can also be interpreted—but only in the sense that it still gets reduced to bytecode first, then that bytecode can be interpreted. 

Go Programming

Go (sometimes called Golang) is scrappy and fresh. It’s an open-source language from Google that made its debut in 2011. 

Go is a statically-typed, multi-paradigm, compiled, and general-purpose programming language just like Java. The language is free and open-source, but developed and maintained by Google. Ken Thompson—one of the primary developers responsible for Go—is well-known for his work in developing Unix operating systems. 

Go’s syntax is deeply similar to C. The compiler for the language was originally written in C but is now written in Go as well, which keeps the language self-hosted. 

Go, as a language, is made for modern multicore computers; it supports concurrent programming. This means it can run multiple processes at the same time. It also has deferred garbage collection that does memory management to keep code speedy.

Comparing Java vs Go

Let’s hold these two languages up to the light and compare them one topic at a time. 

Go vs Java Speed and Readability

Java has been around since 1995 and is used in all manner of devices. Because of this, there is plenty of source code available for reuse. As an added bonus, most of that Java code is open-source, so you can copy, paste, and go. This significantly increases the speed at which you can develop functional applications in Java—assuming there is existing code that fits what you’re trying to accomplish. 

Yet, that history comes with a price tag. So much of that expansive library is outdated. A Java developer might be developing for Java 1.8, and they find just the module they’re looking for… but it’s written in 1.3. They could rewrite it to meet Java 1.8 standards, but that could take more time than writing new code. In addition, the result may be inefficient anyway because that code was written around an older standard. 

Go doesn’t have this problem. Its library is smaller than Java’s, by far, but all of that code works and is written to fit modern standards for development. You’re not left to sort through archives of old modules; it’s built for today’s standards and so is pretty much everything available for it. 

When it comes down to actually typing and reading the code, while they are both C-inspired languages, they have a lot of differences. 

Go code is more compact and unforgiving. It’s built around simplicity and scalability. It pares away unnecessary brackets and parentheses, but it also leaves less leeway for error. This means spending less time typing but (likely) more time debugging. Go is also not object-oriented like Java is. 

Java is more established and stable. It follows the familiar object-oriented principles. That means it’s possible to have ‘reflection,’ where your code can look back at itself at runtime for error checking. 

This is also technically possible in Go—it’s just not as easy to access or implement. 

Java vs Go Performance

When it comes to how quickly Java vs Go run after you’ve typed them, there’s a clear favorite. By most benchmarks, Go’s run time is a bit faster than Java. 

For example, in a test where both languages had to print out a bitmap of a Mandelbrot fractal—Go did it in 5.47 seconds, while Java finished in 6.83 seconds. These aren’t massive differences, but Go keeps this slight lead almost across the board.

Go tends to run faster than Java because it functions like C. It’s compiled to machine code then run directly. 

Java has a second step: it has to be reduced to bytecode by the Java Virtual Machine before it can be compiled to machine code. While this is useful for Java’s application, it slows it down by a couple of seconds in these benchmarking tests. 

Another reason is that Go is good at memory management. It has pointers instead of references. It has garbage collection, which typically slows down executed code; however, Go’s garbage collection is heavily optimized to prevent garbage collection pauses. 

On the other hand, Java’s memory is managed by the virtual machine, and it has more traditional garbage collection that runs every so often. Both work well for memory optimization, but Go’s garbage collection method is just a bit more refined and well-engineered. 

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Go vs Java Application 

Java is built around the idea of ‘write once, run anywhere.` That’s what makes it so portable. The JVM is what interacts with the hardware, so the code (ideally) works in any application. 

This isn’t 100% accurate, and actually launching the same lines of code on any machine is more complex than the ‘write once, run anywhere’ saying implies. However, at its heart, Java is still built around portability, and it is run everywhere; especially in user end devices like ATMs. Java is also the default development language for Android cellphones.

On the flip side, while Go is also designed for simplicity and scalability, Go’s star feature is its excellent multithreading abilities. It’s able to smoothly handle multiple concurrent processes with its ‘goroutines.’ It even has a special mode that runs your code in binary—checking for run race situations. This built-in feature makes sure your code is concurrency safe.

Java also has multithreading abilities, but they just aren’t up to par with Go’s modern, cutting-edge tech. Java’s threads and synchronization primitives get the job done, just not as efficiently as Go’s do. It takes too much memory to make and destroy the threads in Java, and on a server each hit on the website needs its own thread. Most servers can only handle around 1,000 or maybe 10,000 Java threads. With Go, those same servers can handle 100k or more goroutines.

Java vs Go Features

Java’s community has been using the language for a long time. They’ve often requested different features to be added to the language, and many of them have been. Therefore, while the fit isn’t always ideal, Java probably has whatever feature you need that some Java programmer developed somewhere along the way. 

Go, on the other hand, is designed to be simple. It’s supposed to have fewer features, as an intentional feature. Go is intended to be readable by everyone, to use the same or similar code structure as the next programmer so they can pick up where you left off. This might seem a little limiting, but it leads to fewer headaches when developing as a team. 

Java vs Go Communities

Java’s been around a while. I know I keep saying that, but it really does impact every aspect of a programming language. This is especially true when it comes to the community. Java is well-known and has a huge support system in place composed of thousands of developers. If someone developed an app for Android, then they know some Java. Part of the appeal of this community is that it has a lot of veterans. There are people that know Java upside-down and inside-out because they’ve been using it for 20 odd years. 

That doesn’t mean that Golang has no community at all. If Java’s support base is composed of old-timers, then Go’s community has the fresh-faced upstarts. Go is new, so the community is still very excited and active. So while it may not compare to Java’s legacy, you can still find plenty of Go resources, like open-source libraries, example code, and other helpful Go coders. So don’t worry that you might run into a problem without any solution—it’s more than likely someone has already considered or walked the path you’re on, solved, and documented your problem. 

Overall, both Java and Go are powerful and useful, despite their huge differences. Whether you choose the exciting upstart Go, or stick to the well-established mainstay Java, it is completely up to you and what you’re trying to code.