Should I Use `var` in C#? Here's What I've Learned

Hey devs!

So, recently, I was revisiting some of my C# code and stumbled upon a question I've faced multiple times: Should I be using var or explicitly declaring the type? I've seen people debate this back and forth, and I wanted to share my take on it after diving into it a bit deeper.

The Case for var

First off, I'm a fan of var when the type is obvious. Let's be real: repeating the type on both sides of the assignment feels redundant.

var list = new List<string>();

In this case, using var keeps things clean. It's immediately clear we're dealing with a list of strings, and there's no need to clutter the code with unnecessary repetition.

Another good use case? When the type is super long and verbose. Why write out something crazy when var does the trick?

var myData = someService.GetReallyComplicatedType();

Here, I prefer keeping the line simple rather than making my code stretch across the screen.

When to Avoid var

However, there are definitely times when var makes things confusing. One rule I follow is to avoid var when the type isn't immediately obvious. If I (or the next dev looking at the code) can't easily figure out what type it is, I skip var and write the type explicitly.

For example, let's say I have this:

var data = ProcessSomeData(input);

Here, it’s not immediately clear what data is. Could be a string, a custom object, a collection — who knows? In these cases, I prefer being explicit:

CustomType data = ProcessSomeData(input);

Now it's clear what type we're dealing with, which makes the code easier to understand and maintain down the road.

My Take on Best Practices

So, here’s what I’ve landed on for my own code:

• Use var when the type is obvious, like with constructors or when the method name is descriptive enough to imply the return type.
• Avoid var when the type isn’t clear at first glance. Explicit declarations can make code more readable and prevent confusion.

And honestly, it's not just about what looks cleaner. It's also about reducing cognitive load for myself and others. If I'm hunting through code trying to figure out what something is, it's slowing me down. But when it's clear, it keeps me in the flow.

Conclusion

In the end, whether or not to use var comes down to a balance between clarity and brevity. There's no hard rule, and different teams have different preferences. For me, it's all about using var when it makes the code cleaner without sacrificing readability. And if there's any doubt? I stick to explicit types to keep things straightforward.

Would love to hear how you approach this! Do you lean more towards var everywhere, or do you prefer sticking with explicit types? Let me know in the comments.

Happy coding!