Shared coding conventions allow teams to collaborate effectively. While types for lambda arguments are optional, specifying them anyway makes the code clearer and easier to read.

Noncompliant Code Example

Arrays.sort(rosterAsArray,
    (a, b) -> {  // Noncompliant
        return a.getBirthday().compareTo(b.getBirthday());
    }
);

Compliant Solution

Arrays.sort(rosterAsArray,
    (Person a, Person b) -> {
        return a.getBirthday().compareTo(b.getBirthday());
    }
);