⚡ C# Tip: ToCharArray() vs ToArray() — Why It Matters More Than You Think

As developers, we often write code that “just works” — but sometimes, small choices can have a big impact on performance.

One example? The subtle but meaningful difference between ToCharArray() and ToArray() when working with strings in C#. Let’s break it down 👇

🧩 What Each One Does

✅ ToCharArray()

• Native method on the string class.
• Returns a char[].
• Fast and direct.

🚧 ToArray()

• Extension method from LINQ (System.Linq).
• Treats the string as IEnumerable.
• Adds abstraction and intermediate steps.

🔍 The Overhead Problem

Calling ToArray() on a string might seem harmless, but it invokes LINQ under the hood. That means:

• Extra allocations
• Added abstraction
• Unnecessary iteration

Meanwhile, ToCharArray() skips all that and copies the characters directly — with less memory and better performance. In tight loops, I've seen it run 2–3x faster. That adds up.

🧪 When Should You Use Each?

Let’s keep it simple:

👉 Use ToCharArray() when you're working directly with strings — parsing, looping, checking characters, etc.
👉 Use ToArray() when you're working with LINQ and want to convert the result of a query to an array.

Example:

// Using LINQ to filter and convert to array var expensive = products .Where(p => p.Price > 100) .ToArray(); // 👍 This is a perfect case for ToArray() 

💡 Final Thoughts

Is this a micro-optimization? Maybe.
But understanding how your tools work under the hood can make you a better developer — and sometimes, a faster one too.

If this helped or surprised you, give it a share so others don’t fall into the same trap 😄

I’d love to hear your thoughts — have you encountered other subtle performance gotchas in C#?