Question

what I have is a text file that is like this:

apple|2  
turkey|4  
mango|11  
apple|3  
turkey|4  
mango|4  

I need the results to be:

apple|5  
turkey|8  
mango|15  

Any tips or suggestions? I know that there is some Math.Abs and such, I’m just not sure how to combine the lines. Any help would be awesome.

Answer 1

File.WriteAllLines(
    "test.txt",
    File.ReadLines("test.txt")
        .Select(line => line.Split('|'))
        .Select(tokens => new
        {
            Value = int.Parse(tokens[1]),
            Text = tokens[0]
        })
        .GroupBy(li => li.Text)
        .Select(g => string.Format("{0}|{1}", g.Key, g.Sum(l => l.Value)))
        .ToArray()
);

or if you prefer:

File.WriteAllLines(
    "test.txt",
    (from lineItem in
        from line in File.ReadLines("test.txt")
        let tokens = line.Split('|')
        select new
        {
            Value = int.Parse(tokens[1]),
            Text = tokens[0]
        }
    group lineItem by lineItem.Text into g
    let sum = g.Sum(x => x.Value)
    select string.Format("{0}|{1}", g.Key, sum)).ToArray()
);