Java and C# are both object-oriented, statically typed, compiled languages designed to build large, serious applications without everything collapsing into a screaming pile of spaghetti.

They are commonly used for:

• backend web services

• desktop applications

• distributed enterprise systems

• APIs

If you learn one, the other will feel eerily familiar. This is not an accident. C# was created in the early 2000s at Microsoft, very consciously taking inspiration from Java.

Spot the Differences

Let’s start with something comforting: they look almost the same. Hello World:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

class HelloWorld {
    static void Main(string[] args) {
        Console.WriteLine("Hello, World!");
    }
}

What do you notice? The syntax is nearly identical, but the main differences are:

• System.out.println vs Console.WriteLine

• String vs string

• Java insists everything be public class, C# is a bit more relaxed

Types: Strong, Static and very clear about it

Both Java and C# are statically typed. That means the compiler wants to know exactly what kind of thing every variable is.

int age = 25;
String name = "Carol";

int age = 25;
string name = "Carol";

If you try to put a String into an int, both languages will gently but firmly refuse.

C# does add a helpful feature called var:

var age = 25;

This does not at all mean “dynamic typing”. It still knows age is an int; it just saves you some typing. Java eventually added something similar (var in Java 10), but C# embraced this idea earlier and more enthusiastically.

Object Orientation

Both languages are proudly object-oriented. You’ll see:

classes

objects

encapsulation

inheritance

polymorphism

A simple class looks familiar in both:

public class Person {
private String name;

    public Person(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

class Person
{
private string name;

    public Person(string name)
    {
        this.name = name;
    }

    public string GetName()
    {
        return name;
    }
}

Same idea. Same structure. Even the constructor works the same way.

The difference? C# tends to give you nicer tools for the same job.

Properties

C# has a feature called properties that makes getters and setters cleaner: Where Java does this

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

C# does this:

public string Name { get; set; }

Pretty neat right? Same functionality, less boilerplate. Love that.

Learning curve: so what transfers?

If you’vee learned Java, you already understand:

• classes and objects

• interfaces

• collections

• generics

• exceptions

• unit testing concepts

Moving to C# mostly involves learning:

• new keywords

• different libraries

• some nicer syntax

The mental model stays the same. That’s the key thing. I will be making the change myself soon, so I can share my experiences here as they happen. Stay tuned!