Author: Jonas Bilinkevicius

I have a string which contains values separated by "," and not necessarily in 
numeric order (1, 50, 100, 2, 5, 10, ...). What is the best and fastest way to 
search through this string to find a value, for example 100?

Answer:

1   type
2     TIntArray = array of integer
3   
4   procedure StringToIntArray(const S: string; var List: TIntArray);
5   { Converts "S" to an array of integer -> "List" }
6   const
7     ValidChars: set of char = ['0'..'9', '-'];
8   var
9     Ix, Ix2, Len, C: Integer;
10    SubStr: string;
11    Value, Code: Integer;
12  begin
13    Len := Length(S);
14    SetLength(List, Len);
15    if Len = 0 then
16      Exit;
17    C := 0;
18    Ix := 1;
19    while Ix <= Len do
20    begin
21      while (Ix <= Len) and (not (S[Ix] in ValidChars)) do
22        Inc(Ix);
23      Ix2 := Ix;
24      while (Ix <= Len) and (S[Ix] in ValidChars) do
25        Inc(Ix);
26      SubStr := Copy(S, Ix2, Ix - Ix2);
27      Val(SubStr, Value, Code);
28      if Code = 0 then
29      begin
30        List[C] := Value;
31        Inc(C);
32      end;
33    end;
34    SetLength(List, C);
35  end;
36  
37  function FindValue(Value: Integer; List: TIntArray): Integer;
38  { Returns index of requested value, or -1 if not found. }
39  var
40    Ix: Integer;
41  begin
42    Result := -1;
43    Ix := 0;
44    while Ix < Length(List) do
45    begin
46      if List[Ix] = Value then
47      begin
48        Result := Ix;
49        Exit;
50      end;
51      Inc(Ix);
52    end;
53  end;
54  
55  //Example:
56  
57  StringToIntArray('(1, 50, 100, 2, 5, 10,.....)', MyIntArray)

sets the contents of MyIntArray to [1,50,100,2,5,10].
then FindValue(100, MyIntArray) returns 2, as MyIntArray[2] = 100;