var limitations — no fields, no method params, lambda pitfalls?

Local variable type inference

var infers type from initializer—local variables only. Improves readability for verbose generic types but hurts clarity if overused.

• Not for fields, method parameters, or constructor parameters.
• Cannot use without initializer—compiler needs type source.
• Lambdas: var x = (String s) -> s.length() illegal—use explicit param types.
• Avoid var when type carries domain meaning obscured.

var users = new ArrayList<User>(); // ArrayList, not List
List<User> view = users; // widen when passing API