Search code examples
javalistsortingarraylistcollections

How to sort a List/ArrayList?

I have a List of doubles in java and I want to sort ArrayList in descending order.

Input ArrayList is as below:

List<Double> testList = new ArrayList();

testList.add(0.5);
testList.add(0.2);
testList.add(0.9);
testList.add(0.1);
testList.add(0.1);
testList.add(0.1);
testList.add(0.54);
testList.add(0.71);
testList.add(0.71);
testList.add(0.71);
testList.add(0.92);
testList.add(0.12);
testList.add(0.65);
testList.add(0.34);
testList.add(0.62);

The out put should be like this

0.92
0.9
0.71
0.71
0.71
0.65
0.62
0.54
0.5
0.34
0.2
0.12
0.1
0.1
0.1
Solution 
  • Collections.sort(testList);
Collections.reverse(testList);

    That will do what you want. Remember to import Collections though!

    Here is the documentation for Collections.