🚀 Simplify Your C# Collections with the Spread Operator (..)

If you're still using Array.Copy(), .Concat(), or .AddRange() to combine collections in C#, you're working too hard. C# 13 introduced the spread operator (..) that makes collection manipulation cleaner, faster, and more intuitive.

The Problem

Traditional collection operations in C# are verbose and require multiple steps. Whether you're combining arrays, adding elements, or copying collections, you end up with code that's harder to read and maintain.

The Solution: Spread Operator (..)

The spread operator (..) lets you expand collections inline, making your code more expressive and eliminating boilerplate. Think of it as "unpacking" a collection right where you need it.
Code Examples

1️⃣** Basic Collection Combining**

2️⃣ Adding Elements to Collections

3️⃣ Working with Different Collection Types

4️⃣ Real-World Use Case: Building Configuration

5️⃣ Creating Copies

6️⃣ API Response Building

Key Benefits
✅ Readability: Code intention is crystal clear
✅ Less Boilerplate: No more manual array copying or .Concat() chains
✅ Type Safe: Full compile-time type checking
✅ Performance: Efficient memory allocation
✅ Flexibility: Works with any IEnumerable

Performance Comparison

Best Practices
🔹 Use spread operator for:

Combining multiple collections
Creating collection copies
Building collections with mixed sources
Dynamic collection composition

🔹 Remember:

Creates shallow copies (like most collection operations)
Works with any IEnumerable type
Can be mixed with individual elements
Multiple spreads in one expression are fine

🔹 Common Patterns:

Requirements
⚠️ Note: The spread operator requires:

C# 13 or later
.NET 9 or later

If you're on older versions, stick with traditional methods like .Concat(), .AddRange(), or Array.Copy().
When NOT to Use Spread Operator
🔹 If you need to modify elements during combination (use LINQ .Select() instead)
🔹 If you're working with very large collections and need specific performance optimizations
🔹 If you're on C# 12 or earlier (not available)
The Bottom Line
The spread operator is a small syntax addition that makes a huge difference in code clarity. If you're building, combining, or copying collections, stop writing boilerplate and start using ... Your future self (and your code reviewers) will thank you.