TStringList-TStrings Tutorial
TStringList
The TStringList(Or TStrings) is much like a fancy dynamic array or Set of Strings(Not Possible). It will come in handy alot when programming and I'm going to teach you basic TStringList Usage!
<Delphi>program StrList;
var
Str: TStringList;
begin
Str := TStringList.Create; // This is needed when using this class(or most classes) Str.Add('Some String!'); Readln;
end;</Delphi>
This is a simple program(Console) that will create and add one string to a string list! Now heres some things you should know:
Create - Will create the string list for modifying.
Count - Is a counter for the amount of strings in the List. It is a zero based counter
Add - Will allow you to add one string to the string list. It is a Function that will return the Index of the String. This is Were the counter comes in handy.
Delete - Will delete a string from the string list. Just know that you do not simply input the string, you have to input the index of the string.(Like I said. Its like a fancy Dynamic Array)
IndexOf - Will allow you to return the index of the string in the list. If it is not found it returns -1.
Clear - Will clear the list.
Example
How about a more juicy example, Eh?
<Delphi>program StrList;
var
Str: TStringList; S: String; Counter: Integer;
begin
Str := TStringList.Create; Writeln('String List Test'); repeat Writeln('Input a string to add'); Readln(S); if (S = 'EXIT') then Halt; if not (S = ) then begin Counter := Str.Add(S); Writeln('String: ' + S + ' was Added!'); Writeln('Index is: ' + IntToStr(Counter); // The counter will always become the index of the last thing added end rlse Writeln('Nothing Inputed :D'); until (S = 'EXIT');
end;</Delphi>
File Handling
When using the TStringList you have 2 main file handling procedures. SaveToFile And LoadFromFile By Using SavetoFile it will save all strings in the list to a file. LoadFromFile will open the file and add the file data to the list string by string.
<Delphi>var
Str: TStringList;
begin
Str := TStringList.Create; Str.LoadFromFile('SomeFile.txt'); Str.Add('Hello'); Str.SaveToFile('SomeFile.txt');
end;</Delphi>
You just opened a file,edited it and saved it right back to were it was!
Keep Learning
You can learn all the different procedures,functions and property's Here: [1]
IF you feel i might have left something out, Modify At Will!
Hope I helped!