數組排序sortedArrayUsingComparator

按年齡大小排序

- (NSArray *)sortPersonAge:(NSArray<Person *> *)array{

    NSArray *arr = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1,id obj2) {
        Person *person1 = (Person *)obj1;
        Person *person2 = (Person *)obj2;
        return person1.age < person2.age;
    }];
    return arr; //傳回的是排好順序的數組
}