HashMap in Java

HashMap in Java — a practical guide to Java HashMap with clear examples you can reuse in real projects.

Java Tutorial Series (55/90). Prefer one article? Read the complete Java tutorial.

Short description

`HashMap` allows one null key and is unordered. Prefer it for most key/value needs.

HashMap

import java.util.HashMap;

HashMap<String, Integer> ages = new HashMap<>();
ages.put("Asha", 28);
System.out.println(ages.get("Asha"));