常用字符串处理函数

从网络上收集的一些经常会用到的字符串处理函数(基于delphi实现)

１.Get the Position of a string, starting at the end

Code

   
     function LastPos(SearchStr, Str: string): Integer; 
var 
 i: Integer; 
 TempStr: string; 
begin 
 Result := Pos(SearchStr, Str); 
 if Result = 0 then Exit; 
 if (Length(Str) > 0) and (Length(SearchStr) > 0) then 
 begin 
 for i := Length(Str) + Length(SearchStr) - 1 downto Result do 
 begin 
 TempStr := Copy(Str, i, Length(Str)); 
 if Pos(SearchStr, TempStr) > 0 then 
 begin 
 Result := i; 
 break; 
 end; 
 end; 
 end; 
end; 

function LastPos(SubStr, S: string): Integer; 
var 
 Found, Len, Pos: integer; 
begin 
 Pos := Length(S); 
 Len := Length(SubStr); 
 Found := 0; 
 while (Pos > 0) and (Found = 0) do 
 begin 
 if Copy(S, Pos, Len) = SubStr then 
 Found := Pos; 
 Dec(Pos); 
 end; 
 LastPos := Found; 
end; 

 

2.Search for the next occurence of a string from a certain Position

Code

   
     function NextPos(SearchStr, Str: string; Position: Integer): Integer; 
begin 
 Delete(Str, 1, Position - 1); 
 Result := Pos(SearchStr, upperCase(Str)); 
 if Result = 0 then Exit; 
 if (Length(Str) > 0) and (Length(SearchStr) > 0) then 
 Result := Result + Position + 1; 
end; 

3.Get the number of characters from a certain Position to the string to be searched

Code

   
     function NextPosRel(SearchStr, Str: string; Position: Integer): Integer; 
begin 
 Delete(Str, 1, Position - 1); 
 Result := Pos(SearchStr, UpperCase(Str)) - 1; 
end;