How to sort array of strings by their lengths

Question

I have an array of strings such as "blue", "green", "red" and I wish to sort them so the longest string comes first and the shortest last.

Currently I am creating another array with the lengths of each string in the array in the same index positions and using this array as the key array to sort by as can be seen below, but I think this could be optimised into one line perhaps?

Dim colours() As string = {"blue", "green", "red"}
Dim colourslength() As Integer
For i As Integer = 0 To colours.Length - 1
 colourslength(i) = colours(i).Length
Next
Array.Sort(colourslength, colours)
Array.Reverse(colours)

Edit: just realised I defined colours as a list in the example code, it's an array in my actual code.

@davisoa: I would guess .net 4 as that inline list initialization isn't valid in earlier versions. — Jon Egerton
– Jon Egerton, Commented Apr 4, 2012 at 15:45
it is .net 4, I used a list by accident though, sorry about that. — Marcus Lars
– Marcus Lars, Commented Apr 4, 2012 at 15:54

Meta-Knight · Accepted Answer · 2012-04-04 16:19:35Z

5

Another Linq solution (warning, converted from C#)

Dim Sorted = From p In colours Order By p.Length Descending Select p

edited Apr 4, 2012 at 16:19

Meta-Knight

17.9k1 gold badge51 silver badges60 bronze badges

answered Apr 4, 2012 at 15:45

Steve Wellens

20.6k2 gold badges31 silver badges70 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Oybek Over a year ago

Dim q = From el In colours Order By el.Length Descending. Select is not compulsory in VB.NET. If omitted the element of the selection will be the element type )).

Oybek · Accepted Answer · 2012-04-04 15:41:35Z

3

To my opinion this is the shortes way. Use linq.

Dim strs = New String() {"", "333", "22", "4444", "55555", "1"}
Dim sorted = strs.OrderBy(Function(x) x.Length).ThenBy(Function(x) x).ToArray()

Edit

If you want a reverse order just get rid of extra method call an do the sortin in a reverse order

Dim strs = New String() {"", "333", "22", "4444", "55555", "1"}
Dim sorted = strs.OrderByDescending(Function(x) x.Length).ThenByDescending(Function(x) x).ToArray

Cheers.

answered Apr 4, 2012 at 15:41

Oybek

7,2945 gold badges32 silver badges50 bronze badges

3 Comments

Jon Egerton Over a year ago

The OrderBy needs to be OrderByDescending as he wants longest first.

Marcus Lars Over a year ago

Could you explain what the second part of this line does? Dim sorted = strs.OrderByDescending(Function(x) x.Length).ThenByDescending(Function(x) x).ToArray the ThenByDescending(Function(x) x) part. I'm reading it that the first part of that line does the actual sorting?

Oybek Over a year ago

@MarcusLars, OrderByDescending(Function(x) x.Length) order by length. ThenBy is applied when there are strings with equal length. Two equal length strings will be sorted alphabetically.

Meta-Knight · Accepted Answer · 2012-04-04 15:43:00Z

3

Dim colours = {"blue", "green", "red"}
Dim coloursSortedByLength = colours.OrderByDescending(Function(c) c.Length)

Output sequence is: green, blue, red.

answered Apr 4, 2012 at 15:43

Meta-Knight

17.9k1 gold badge51 silver badges60 bronze badges

Comments

Gabber · Accepted Answer · 2012-04-05 15:45:13Z

2

The best simple way to do it, is to compare every string with all other strings in your list:

in Java:

for(int i=0; i<list.length-1; i++){
    for(int j=i+1; j<list.length; j++){
        if(list[i].length() < list[j].length()){
            tmp = list[i];
            list[i] = list[j];
            list[j] = tmp;
        }
    }
}

edited Apr 5, 2012 at 15:45

Gabber

5,5227 gold badges37 silver badges49 bronze badges

answered Apr 4, 2012 at 15:49

Ahmed Laatabi

9371 gold badge8 silver badges24 bronze badges

Collectives™ on Stack Overflow

How to sort array of strings by their lengths

4 Answers 4

1 Comment

3 Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

3 Comments

Comments

Comments

Related