C# Feature - ref locals

Overview

Ref locals let a local variable alias another storage location, which avoids copying and can allow in-place updates.

Introduced In

C# 7.0 (2017)

Before

var item = values[0];
item++;

After

ref int item = ref values[0];
item++;

Gotchas & Best Practices

• Use ref locals only when aliasing is intentional and clearly beneficial.
• Overuse can make code harder to reason about than ordinary value copies.