Question

I have a string variable that contain [l=9;f=0;r=5;p=2]. There are may be a more than one:[l=9;f=0;r=5;p=2],[l=9;f=0;r=6;p=2].

I want to get List of Tuple<int,int,int>, where item1 = value of l, item2= value of r, item3=value of p. What is best approach to do this?
My code:

  // split string
    var splittedFormatedSeats = Regex.Matches(formatSeats, @"\[.+?\]")
                            .Cast<Match>()
                            .Select(m => m.Value)
                            .ToList();


     IList<Tuple<int,int,int>> fullSeat = new List<Tuple<int, int, int>>();
       foreach (var splittedFormatedSeat in splittedFormatedSeats)
       {

          ...
       }

Thanks.

Answer 1

I would adopt another strategy. First, split subcomponents of your string

var components = formatSeats.Split(',');

This will give you an array of string. This will be far more efficient to parse small chunks of strings instead of a big string.

You can then use either a Regex to extract the values or a simple code like this :

foreach(var component in components)
{
    var parts = component.Trim("[]".ToCharArray()).Split(';');

}

var results = from component in components
              let c = component.Trim("[]".ToCharArray())
                               .Split(';')
                               .Select(c=>int.Parse(c.SubString(2))
              select new { l = c[0], f=c[1], r=c[2], p = c[3] };

This will produces an enumeration of an anonymous type.

foreach(var x in results)
{
    Console.WriteLine("{0} / {1} / {2} / {3}", x.l, x.f, x.r, x.p);
}

If you actually need a Tuple simply change the code to :

var results = from component in components
              let c = component.Trim("[]".ToCharArray())
                               .Split(';')
                               .Select(c=>int.Parse(c.SubString(2))
              select new Tuple<int,int,int,int>{ l = c[0], f=c[1], r=c[2], p = c[3] };

I would however, advocate for writing a small struct to simplify the code and raise its readability.

public struct MyValue
{
     private readonly int m_L; 
     public int L { get {return m_L; } }

     private readonly int m_F; 
     public int F { get {return m_F; } }

     private readonly int m_R; 
     public int R { get {return m_R; } }

     private readonly int m_P; 
     public int P { get {return m_P; } }

     public MyValue(int l, int f, int r, int p)
     {
         m_L = l;
         m_F = f;
         m_R = r;
         m_P = p;
     }
}
....


var results = from component in components
          let c = component.Trim("[]".ToCharArray())
                           .Split(';')
                           .Select(c=>int.Parse(c.SubString(2))
          select new MyValue(c[0],c[1],c[2],c[3]);

Finally, if the string always have this form, you could avoid using the Regex.