CODEWITHSUNDEEP
c#arrayslist
FLF
FLF

Reputation: 157

Sorting of list Composed of array

am in a middle of project , and am kind of stuck on the problem,

i need to sort a list in C# the list structure is
public List < double[] > DataList = new List < double[] >();

now i want to sort this list on the bases of the last index of double array in the list

like

2|3|5|6|8

2|3|5|6|9

2|3|5|6|5

2|3|5|6|12

the output should be some thing like this

2|3|5|6|12

2|3|5|6|9

2|3|5|6|8

2|3|5|6|5

Upvotes: 0

Views: 151

Answers (3)

Nikola Davidovic
Nikola Davidovic

Reputation: 8656

This is some old school sorting without using the LINQ.

        List<double[]> DataList = new List<double[]>();
        private void button1_Click(object sender, EventArgs e)
        {
            DataList.Add(new double[] { 2, 3, 5, 6, 8 });
            DataList.Add(new double[] { 2, 3, 5, 6, 9 });
            DataList.Add(new double[] { 2, 3, 5, 6, 5 });
            DataList.Add(new double[] { 2, 3, 5, 6, 12 });
            DataList.Sort(new DoubleArrayComparer());
            DataList.Reverse();
        }
        class DoubleArrayComparer : IComparer<double[]>
        {
            public int Compare(double[] x, double[] y)
            {
                if(x.Length>0 && y.Length>0)
                {
                    if(x[x.Length-1] > y[y.Length-1])
                        return 1;
                    else if(x[x.Length-1] < y[y.Length-1])
                        return -1;
                    else
                        return 0;

                }
                else if(x.Length == 0 && y.Length!=0)
                    return -1;
                else if(y.Length == 0 && x.Length!=0)
                    return 1;
                else
                    return 0;
            }
        }

Upvotes: -1

user2076992
user2076992

Reputation:

Also using Linq:

var tList = new List<double[]>();
tList.Add(new double[] {2,3,4,5,8});
tList.Add(new double[] {2,3,4,5,9});
tList.Add(new double[] {2,3,4,5,5});
tList.Add(new double[] {2,3,4,5,12});

var t = from element in tList
        orderby element.Last() descending
        select element;
var tResults = t.ToList();

Upvotes: 0

Juli&#225;n Urbano
Juli&#225;n Urbano

Reputation: 8488

Use LINQ:

// reproduce data
List<double[]> DataList = new List<double[]>();
DataList.Add(new double[] { 2, 3, 5, 6, 8 });
DataList.Add(new double[] { 2, 3, 5, 6, 9 });
DataList.Add(new double[] { 2, 3, 5, 6, 5 });
DataList.Add(new double[] { 2, 3, 5, 6, 12 });

var ordered = DataList.OrderByDescending(l => l.Last());

l would correspond to each element in DataList. With l.Last() you use the last element as sorting criterion.

Upvotes: 3

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