fbasfunction.pas

代码齐全

unit FBasFunction;

interface

Function Left(inString : String; numChars : Byte) : String;
Function Right(inString : String; numChars : Byte) : String;
Function SubStr(inString : String; numChars, strSize : Byte) : String;

implementation

{+-------------------------------------------------------+}
{: Function :  LEFT                                      :}
{+-------------------------------------------------------+}
{:    Syntax : LEFT ( <expC> , <expN> )                  :}
{:                                                       :}
{:     where : <expC> = character string                 :}
{:             <expN> = number of characters to return   :}
{:                      Integer value                    :}
{:                                                       :}
{:    Action : Returns a specified number of characters  :}
{:             in the character string <expC>, starting  :}
{:             from the leftmost character.              :}
{:                                                       :}
{: Result Type :  String                                 :}
{+-------------------------------------------------------+}
Function Left;
Begin
  Left := Copy(inString,1,numChars)
End;

{+-------------------------------------------------------+}
{: Function :  RIGHT                                     :}
{+-------------------------------------------------------+}
{:    Syntax : RIGHT ( <expC> , <expN> )                 :}
{:                                                       :}
{:     where : <expC> = character string                 :}
{:             <expN> = number of characters to return   :}
{:                      Integer value                    :}
{:                                                       :}
{:    Action : Returns the rightmost <expN> portion of a :}
{:             character string <expC>                   :}
{:                                                       :}
{: Result Type :  String                                 :}
{+-------------------------------------------------------+}
Function Right;
Var
  index : Byte;
Begin
  If numChars >= Length(inString) Then
    Right := inString
  Else
    Begin
      index := Length(inString) - numChars+1;
      Right := Copy(inString,index,numChars)
    End
End;

{+-------------------------------------------------------+}
{: Function :  SUBSTR                                    :}
{+-------------------------------------------------------+}
{:    Syntax : SUBSTR ( <expC>, <expN1>[, <expN2>] )     :}
{:                                                       :}
{:     where : <expC> = character string                 :}
{:             <expN1>,<expN2> = numeric value (Byte)    :}
{:                                                       :}
{:    Action : Returns a string of length <expN2> from   :}
{:             <expC>, beginning with the <expN1>th      :}
{:             character.  The <expN1> and <expN2> must  :}
{:             be in the range 1 to 255.  If <expN2> is  :}
{:             omitted or if there is fewer than <expN2> :}
{:             characters to the right of the <expN1>th  :}
{:             character, all rightmost characters       :}
{:             beginning with the <expN1>th character are:}
{:             returned.  If <expN1> is greater than the :}
{:             number of characters in <expC>, SUBSTR    :}
{:             returns a null string.                    :}
{:                                                       :}
{: Result Type :  String                                 :}
{+-------------------------------------------------------+}
Function SubStr;
Begin
  SubStr := Copy(inString, numChars, StrSize );
End;

end.