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JavaBeginner#generics
JavaIntermediate#collections
How do you sort a List of custom objects by multiple fields?
Use Comparator.comparing() chained with thenComparing() to define a primary sort key followed by tie-breaking keys, applied via List.sort() or Collections.sort().
Example
list.sort(Comparator.comparing(Person::getLastName) .thenComparing(Person::getFirstName));