Arraylist in c#

arjunan selvam

how to get values in the arraylist from the user at run time?The user might enter string or integer.i want to get those values from the user and display?

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
If you've no idea whether a particular element of the ArrayList (say the first) contains a string or an integer, then you can use code like this to recover and display it:

object obj = arrayList[0];

if (obj.GetType() = typeof(int))
{
int myInt = (int)obj;
Console.WriteLine("An integer value, {0}, was entered first", myInt);
}
else
{
string myString = (string)obj;
Console.WriteLine("A string value, {0}, was entered first", myString);
}
Akkiraju Ivaturi14y ago
Though it is possible but error prone when used incorrectly as per Microsoft. Follow the link:

http://msdn.microsoft.com/en-us/library/b5bx6xee.aspx

If still you would like to use ArrayList then try to do like this (but not recommended and it will lead to exceptions if used improperly):

System.Collections.ArrayList list = new System.Collections.ArrayList();
string userInput = Console.ReadLine();
double num;
bool isNum = double.TryParse( userInput , out Num);

if(isNum)
list.add(num);
else
list.add(userInput);

Instead of this try to create a generic type List collection and whether user enters number or string you can accommodate that in a string type as below:

List list = new List();

Whenever you need to do any number operation, loop through and check if the string value can be converted to number and perform it which I do not think you will be doing. If you try to do same operation on both string and number you will get exception as mentioned in the above link.

Let me know if you have any questions.