DotNetCode: Difference and performance between Array and ArrayList in C#

Arrays:

Arrays are fixed size .
It’s used the namespace as System.
Array cannot resize automatically.
But in Vb.net array can resize themself by using ReDim Statement.When using ReDime array can losses the data and its modify the array structure as mention in the ReDim statement.
But this ReDim statement is not available in C#.
Array has contains one data type i.e. Homogenous data type.
Arrays are multidimensional.
The data in an array is accessed by indexes.
For performance always recommended using arrays.
If you delete an item in an array, it keeps that position empty, its wait for anther data to fill the positions.

Syntax:

string[] str = new string[5];

str[0] = "DotNet";

str[1] = "DotnetCode";

ArrayList:

ArrayList are variable in size.
It’s used the namespace as System .Collections
ArrayList grows automatically i.e. the numbers of items are added to the arrayList.
ArrayList contain many data types i.e. heterogenous data type. In a single Arraylist we can store any data type - integer, string and any type of object inherited from System.Object.
ArrayList is always single-dimensional.
If you delete an item in an arraylist, that position is occupied by the next element.
We can add, insert and delete items into an ArrayList.

Syntax:

ArrayList astr = new ArrayList();

astr.Add("str");

astr.Remove("str");

astr.RemoveAt(0);

Check the performance between Array and ArrayList in C#

int[] rate = new int[501];

ArrayList str1 = new ArrayList();

Stopwatch watch = new Stopwatch();

watch.Start();

for (int i = 0; i <= 500; i++)

{

rate[i] = i;

}

watch.Stop();

Response.Write("ARRAY SECONDS :" + watch.Elapsed.TotalMilliseconds);

watch.Reset();

watch.Start();

for (int i = 0; i <= 500; i++)

{

str1.Add(i);

}

watch.Stop();

Response.Write("ARRAYLIST SECONDS :" + watch.Elapsed.TotalMilliseconds);

Result :

When compare Performance array is better than ArrayList

ARRAY SECONDS :0.0035ARRAYLIST SECONDS :0.0194

Post your comments here….

DotNetCode