Sorting an Array
You can sort an array in Java with
Sort an array
The static method java.util.Arrays.sort can be used if the sort is simple:
Sort the list 2,7,5,4.
Sort an array using a custom comparator
You can create your own comparator. This means that you decide how the sort is to be done.
You must implement the
compare method - this returns a negative, zero or a positive
integer depending on how o1 compares to o2.
return -1 (or any negative number) if o1 comes before o2 return 0 if o1 and o2 are the same return 1 (or any positive number) if o1 comes after o2
Sort an array using an anonymous custom comparator
This is essentially the same as the above - but you do not need to explicitly name the comparator.
Sort an ArrayList
For an ArrayList (or any List) you use Collections.sort
Sort an ArrayList using a Custom Comparator
In this example you can sort an ArrayList of List. Notice that the output is ordered by region:
[[Angola, Africa, 1250000, 14500000, 14935000000], [Benin, Africa, 112622, 7100000, 3763000000], [Botswana, Africa, 581730, 1800000, 7812000000], ...