C# Feature – var (Implicit typing)

Overview

var lets the compiler infer the exact type of a local variable from the initializer, improving readability without sacrificing static types.

Introduced In

C# 3 (2007)

Before

Dictionary<string, List<int>> map = new Dictionary<string, List<int>>();

After

var map = new Dictionary<string, List<int>>();

Annotated Example

var n = 42; // int
var s = "text"; // string

Gotchas & Best Practices

• Don’t overuse; keep clarity. Avoid var when the type is not obvious from the right-hand side.

Related Features

• Language Fundamentals

Version Notes

• Works with target-typed new (C# 9).