C# How to remove element from the regular array

Question

I am using a regular array which has 5 elements I want to remove the element but I don't want to use any collection such as arrayList or List

My code is

for (int c = 0; c < Alpha.Length; c++)
{
    if (Alpha[c].Power< 0)
    {
      //  Alpha.s = null;
    }
}

You can't remove element from regular array. All you can - assign some value to element, or create new array and copy all other items there. That's why collections are handy — Sergey Berezovskiy
– Sergey Berezovskiy, Commented Sep 9, 2013 at 12:17
You want to remove an item and sort the others, so the array dont get null values on is middle? — Marciano.Andrade
– Marciano.Andrade, Commented Sep 9, 2013 at 12:41

Ahmed KRAIEM · Accepted Answer · 2013-09-09 12:30:56Z

10

From MSDN

The number of dimensions and the length of each dimension are established when the array instance is created. These values can't be changed during the lifetime of the instance.

(Emphasis mine).

Arrays, by design, have a fixed size in C#, so a new array should be allocated:

Alpha = Alpha.Where(a => a.Power >= 0).ToArray();

Without Linq:

TheType[] alpha2 = new TheType[Alpha.Length];
int j=0;
for (int i=0; i < Alpha.Length; i++)
    if(Alpha[i].Power >= 0)
    {
        alphaTmp[j++] = Alpha[i];
    }
Array.Resize(ref alphaTmp, j);
Alpha = alphaTmp;

edited Sep 9, 2013 at 12:30

answered Sep 9, 2013 at 12:16

Ahmed KRAIEM

10.4k4 gold badges32 silver badges33 bronze badges

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

5 Comments

MarcinJuraszek Over a year ago

It will create new array with proper elements. But because you can't change array size without recreating it I think it's really a good way to go here (but using List<T> would be better anyway).

Ahmed KRAIEM Over a year ago

There is no use of collections here. There is only the use of linq.

Kendall Frey Over a year ago

@user2740970 Not LINQ either? You certainly have strict (and strange) requirements.

user2740970 Over a year ago

thats the problem no linq and collection otherwise i would have used List<>

Ahmed KRAIEM Over a year ago

What version of .Net are you targeting?

Jon Skeet · Accepted Answer · 2013-09-09 12:17:31Z

6

You can't "remove" an element from an array in terms of any operation which changes the length of the array: once an array has been created, its length is fixed. Options:

Change the element value to null, or some other appropriate value
Shift all the other elements towards the head and set the last element value to null etc
Create a new array with a smaller length, potentially assigning it back to the variable/property which originally referred to the larger array

It's unclear why you're rejecting the normal collections though. You should think about this decision very carefully - using the built-in collection types is almost always a better solution.

answered Sep 9, 2013 at 12:17

Jon Skeet

1.5m893 gold badges9.3k silver badges9.3k bronze badges

Comments

user2160375 · Accepted Answer · 2013-09-09 12:20:23Z

1

You can use LINQ:

Alpha = Alpha.Where(ob => bo.Power >= 0).ToArray();

Remember - it will create a new array.

BTW. Why you don't want to use List<T>?

answered Sep 9, 2013 at 12:20

user2160375

1 Comment

user2740970 Over a year ago

i dont want to use collection and linq

Collectives™ on Stack Overflow

C# How to remove element from the regular array

3 Answers 3

5 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

5 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related