removing duplicated text inside a string

Question

i have string that got some text like this

str := 'Hi there My name is Vlark and this is my images <img src=""><img src=""> But This images need to be controlled <img src=""><img src=""><img src=""><img src="">'; 

this string have 6 images tags <img i wanted to control on this tags so if this string have more than 3 images tags leave the first three and remove the rest image tags . i couldnt figure out how can i do that in coding

Answer 1

Strategy:

• Find position and length of complete enclosed tags: <img and >
• If count larger than 3, remove tag.

---

function RemoveExcessiveTags( const s: String): String;
var
  tags,cP,p : Integer;
begin
  tags := 0;
  cP := 1;
  Result := s;
  repeat
    cP := Pos('<img',Result,cP);
    if (cP > 0) then begin
     // Find end of tag
      p := Pos('>',Result,cP+4);
      if (p > 0) then begin
        Inc(tags);
        if (tags > 3) then begin // Delete tag if more than 3 tags
          Delete(Result,cP,p-cP+1);
        end
        else
          cP := p+1;  // Next search start position
      end
      else
        cP := 0;  // We reached end of string, abort search
    end;
  until (cP = 0);
end;