Is Array.Sort() able to sort this (and save the indexes)?

Hi, I have a double 2D array:

a[0,0]=1.1	a[0,1]=0.1	a[0,2]=2.9	a[0,3]=1.6
a[1,0]=-2.2	a[1,1]=-1.7	a[1,2]=0.3	a[1,3]=-0.4
a[2,0]=2.0	a[2,1]=-0.1	a[2,2]=-1.8	a[2,3]=-3.1

1) I want to sort it in descending order AND save the 2 indexes (in order to know which array indexes has the absolute higher/lower values):

a[2,3]=-3.1
a[0,2]=2.9
a[1,0]=-2.2
a[2,0]=2.0
a[2,2]=-1.8
a[1,1]=-1.7
a[0,3]=1.6
a[0,0]=1.1
a[1,3]=-0.4
a[1,2]=0.3
a[0,1]=0.1
a[2,1]=-0.1

2) I also need another sort: on the first index and save the 2nd index:

a[0,2]=2.9
a[0,3]=1.6
a[0,0]=1.1
a[0,1]=0.1

a[1,0]=-2.2
a[1,1]=-1.7
a[1,3]=-0.4
a[1,2]=0.3

a[2,3]=-3.1
a[2,0]=2.0
a[2,2]=-1.8
a[2,1]=-0.1

Is it possible with "Array.Sort()" ? As a beginner, help will be greatly appreciated!

Thank you very much!

Hello,

If You need to sort values inside 2d array, only by first column, or only by second column,

It is possible by using Array.Sort(Key, Values) method, read article at this url :

https://www.dotnetperls.com/array-sort

If that does not help, here are some usefull links with different array sort approach. :

https://www.c-sharpcorner.com/article/how-to-sort/

https://www.c-sharpcorner.com/article/working-with-arrays-in-C-Sharp/

https://www.c-sharpcorner.com/search.aspx?q=C%23%20sort

PS.

If there is no need to use Array.Sort() method,

I strongly recomend to observe double array problem as simple use of 2d array with four columns.

First and second column shall contain array indexes, third and fourth column shall contains array values.

Than all You need is to sort that array by wanted columns in selected sort order.

According to that above double array shall look like this :

0,0,1,1

0,1,0,1

0,2,2,9

0,3,1,6

----------

2.2.1.8

2,3,3,1

To solve first problem,

sort array above by column three in descending sort order,

then by column four in descending sort order.

To solve second problem,

sort array above by column one in ascending sort order,

then by column three in descending sort order,

then by column four in descending sort order,

then by column two in ascending sort order.

Method for such sort is explained at article at this url :

https://www.c-sharpcorner.com/article/how-to-sort/

All the best,

Željko Peric

1 Reply

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Željko Perić6y ago
Hello,

If You need to sort values inside 2d array, only by first column, or only by second column,
It is possible by using Array.Sort(Key, Values) method, read article at this url :

https://www.dotnetperls.com/array-sort

If that does not help, here are some usefull links with different array sort approach. :

https://www.c-sharpcorner.com/article/how-to-sort/

https://www.c-sharpcorner.com/article/working-with-arrays-in-C-Sharp/

https://www.c-sharpcorner.com/search.aspx?q=C%23%20sort

PS.
If there is no need to use Array.Sort() method,
I strongly recomend to observe double array problem as simple use of 2d array with four columns.
First and second column shall contain array indexes, third and fourth column shall contains array values.
Than all You need is to sort that array by wanted columns in selected sort order.

According to that above double array shall look like this :

   0,0,1,1
   0,1,0,1
   0,2,2,9
   0,3,1,6
   ----------
   ----------
   2.2.1.8
   2,3,3,1

To solve first problem,
sort array above by column three in descending sort order,
then by column four in descending sort order.

To solve second problem,
sort array above by column one in ascending sort order,
then by column three in descending sort order,
then by column four in descending sort order,
then by column two in ascending sort order.

Method for such sort is explained at article at this url :

https://www.c-sharpcorner.com/article/how-to-sort/

All the best,
Željko Peric