var, final & Wrappers in Java
From the Java cheat sheet · Variables & Data Types · verified Jul 2026
var, final & Wrappers
Local type inference, constants, casting, and boxed types.
java
// Quick Reference
var name = "Sam"; // inferred as String
final int MAX = 100; // constant, cannot reassign
Integer boxed = 42; // wrapper object (nullable)💡 var only works for local variables with an initializer, not fields or params.
⚡ Wrapper types (Integer, Double) can be null; primitives cannot.
📌 Prefer primitives for performance; use wrappers when you need null or generics.
🟢 Narrowing casts (double -> int) truncate and must be explicit with (type).
varfinalwrappers
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