Tutorial by Examples

the spaceship operator returns -1 when the left operator is smaller, 0 when the operators are equal and 1 otherwise: assert 10 <=> 20 == -1 assert 10 <=> 10 ​== 0 assert 30 <=> 10 == 1 assert 'a' <=> 'b' == -1 assert 'a' <=> 'a'​== 0 assert 'b' <=> 'a' == ...

class User { String name int age } def users = [ new User(name: "Bob", age: 20), new User(name: "Tom", age: 50), new User(name: "Bill", age: 45) ] // sort by age users.sort { a, b -> a.age <=> b.age }

Comparator cmp = [ compare:{ a, b -> a <=> b } ] as Comparator def col = [ 'aa', 'aa', 'nn', '00' ] SortedSet sorted = new TreeSet( cmp ) sorted.addAll col assert '[00, aa, nn]' == sorted.toString()