CODEWITHSUNDEEP
c#arraylist
user2800287
user2800287

Reputation: 55

Check if Characters in ArrayList C# exist - C# (2.0)

I was wondering if there is a way in an ArrayList that I can search to see if the record contains a certain characters, If so then grab the whole entire sentence and put in into a string. For Example:

list[0] = "C:\Test3\One_Title_Here.pdf";
list[1] = "D:\Two_Here.pdf";
list[2] = "C:\Test\Hmmm_Joke.pdf";
list[3] = "C:\Test2\Testing.pdf";

Looking for: "Hmmm_Joke.pdf"
Want to get: "C:\Test\Hmmm_Joke.pdf" and put it in the Remove()

    protected void RemoveOther(ArrayList list, string Field)
    {
        string removeStr;

        -- Put code in here to search for part of a string which is Field --
        -- Grab that string here and put it into a new variable --
        list.Contains();
        list.Remove(removeStr);

    }

Hope this makes sense. Thanks.

Upvotes: 1

Views: 1943

Answers (4)

Dorival
Dorival

Reputation: 689

I would rather use LINQ to solve this. Since IEnumerables are immutable, we should first get what we want removed and then, remove it.

        var toDelete = Array.FindAll(list.ToArray(), s =>
            s.ToString().IndexOf("Hmmm_Joke.pdf", StringComparison.OrdinalIgnoreCase) >= 0
            ).ToList();

        toDelete.ForEach(item => list.Remove(item));

Of course, use a variable where is hardcoded.

I would also recommend read this question: Case insensitive 'Contains(string)' It discuss the proper way to work with characters, since convert to Upper case/Lower case since it costs a lot of performance and may result in unexpected behaviours when dealing with file names like: 文書.pdf

Upvotes: 0

Casperah
Casperah

Reputation: 4554

This will do the job without raising an InvalidOperationException:

string searchString = "Hmmm_Joke.pdf";
foreach (string item in list.ToArray())
{
    if (item.IndexOf(searchString, StringComparison.OrdinalIgnoreCase) >= 0)
    {
        list.Remove(item);
    }
}

I also made it case insensitive.

Good luck with your task.

Upvotes: 0

Karl Anderson
Karl Anderson

Reputation: 34846

Loop through each string in the array list and if the string does not contain the search term then add it to new list, like this:

string searchString = "Hmmm_Joke.pdf";
ArrayList newList = new ArrayList();

foreach(string item in list)
{
    if(!item.ToLower().Contains(searchString.ToLower()))
    {
        newList.Add(item);
    }
}

Now you can work with the new list that has excluded any matches of the search string value.

Note: Made string be lowercase for comparison to avoid casing issues.

Upvotes: 4

JG in SD
JG in SD

Reputation: 5607

In order to remove a value from your ArrayList you'll need to loop through the values and check each one to see if it contains the desired value. Keep track of that index, or indexes if there are many.

Then after you have found all of the values you wish to remove, you can call ArrayList.RemoveAt to remove the values you want. If you are removing multiple values, start with the largest index and then process the smaller indexes, otherwise, the indexes will be off if you remove the smallest first.

Upvotes: 1

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