SysUtils.StrScan、SysUtils.StrRScan、SysUtils.StrPos

StrScan  : 返回一个字符在一个 PChar 串中第一次出现的位置指针;
StrRScan : 返回一个字符在一个 PChar 串中最后一次出现的位置指针;
StrPos   : 返回一个 PChar 串在另一个 PChar 串中第一次出现的位置指针.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

//StrScan、StrRScan:
procedure TForm1.Button1Click(Sender: TObject);
var
  p: PChar;
  str: string;
begin
  str := 'ABCBBBCBA';
  p := StrScan(PChar(str), 'B');
  ShowMessage(p);  {BCBBBCBA}

  p := StrRScan(PChar(str), 'B');
  ShowMessage(p);  {BA}
end;

//StrPos:
procedure TForm1.Button2Click(Sender: TObject);
var
  p: PChar;
  str: string;
begin
  str := '123456789';
  p := StrPos(PChar(str), '456');
  ShowMessage(p); {456789}
end;

end.

SysUtils 单元下的公用函数目录

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