Filtering strings out of an array

Question

I'm trying to design a check on incoming strings for an array, and if the incoming string has a specific starting character it gets skipped over

For example:

;item1
item2
item3
;item4

should be put into array as

item2
item3

I thought I'd try to use a foreach method to skip the line that starts with the identifier, and then in the else append the lines that don't match back into the string array, but it doesn't seem I am able to do this.

Help!

    void Whitelist()
    {
        if (logging == 1)
        {
            FIO._Log("Performing WhiteList func", writer);
        }
        try
        {
            string[] lines = File.ReadAllLines("Whitelist.ini");
            string[] lines2;
            foreach (string line in lines)
            {
                if (line.StartsWith(";"))
                {
                    continue;
                }
                else
                {
                    // lines2.append(line) ??
                }

            }
            structs.CustomWhiteList = lines2;
        }
        catch (Exception e)
        {
            MessageBox.Show("Error reading whitelist file." + Environment.NewLine + e.Message);
            FIO._Log("Failed to read whitelist file", writer);
        }
    }

You have an array, not a list. There's no "Add" or "Append" method. But everything can be shortened to lines2 = lines.Where(l => !l.StartsWith(";")); — Pierre-Luc Pineault
– Pierre-Luc Pineault, Commented Aug 4, 2014 at 3:11

Grant Winney · Accepted Answer · 2014-08-04 03:13:10Z

2

You can read the lines in, filter out the ones starting with a semicolon, and then set the resulting array directly to CustomWhiteList.

Try the following code:

var lines = File.ReadAllLines("Whitelist.ini");

structs.CustomWhiteList = lines.Where(x => !x.StartsWith(";")).ToArray();

This uses LINQ, so you'll have to add using System.Linq to your class if it's not already there.

answered Aug 4, 2014 at 3:13

Grant Winney

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1 Comment

Sean Over a year ago

Oh my goodness, thank you! Everyone had good answers, but this one was so simple, and you answered me so fast.

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