Sort string array by element length

Question

Having an array of strings how can I update it so its elements are sorted by its length.

I was trying

string[] arr = {"aa","ss","a","abc"};
arr = arr.OrderBy(aux => aux.Length);

So, I would get a,aa,ss,abc, but it says

cannot implicitly convert type 'system.linq.iorderedenumerable to string[]'

So, I was doing

foreach (string s in arr.OrderBy(str => str.Length))
{
    //
}

Is there other way to do this?

Solution 1

Since arr is an array, you can use the convenient Array.Sort method:

Array.Sort(arr, (x, y) => x.Length.CompareTo(y.Length));
foreach (string s in arr)
{
    ...
}

This is more efficient than OrderBy as it will sort the elements of the array in place rather than creating a new collection to enumerate.

Solution 2

OrderBy returns IEnumerable, not an array. Use ToArray method to get an array:

arr = arr.OrderBy(aux => aux.Length).ToArray();

However, it will not sort the source array. Instead of that, it will create a new one with items sorted and replace the reference. If you need in-place sort (e.g. when the array is also referenced elsewhere) use Array.Sort method:

Array.Sort(x, (x1, x2) => x1.Length.CompareTo(x2.Length));

Solution 3

You can also do this using Linq as below:

var sortedElements = from arrElement in arr.Distinct()
                     orderby arrElement.Length
                     select arrElement;

foreach (string element in sortedElements)
{
     ...
}

Comments

[ePandit]

This is the only method I found, to sort array lengthwise without using Linq and also without creating another array (or any other collection).