Delphi Length函数

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  arrayA: array of Integer;
  arrayB: array[0..5] of Integer;
  s1: string;
  s2: WideString;
  s3: string[30];

begin
  SetLength(arrayA, 3);
  ShowMessage(IntToStr(Length(arrayA)));      //用Length取得动态数组的长度
  ShowMessage(IntToStr(Length(arrayB)));      //用Length取得静态数组的长度

  s1 := ‘你好！‘;
  s2 := ‘你好！‘;
  s3 := ‘你好！‘;
  ShowMessage(IntToStr(Length(s1)));          //用length 取得AnsiString的实际使用长度
  ShowMessage(IntToStr(Length(s2)));          //用Length取得WideString的实际使用长度
  ShowMessage(IntToStr(Length(s3)));          //Length只能取得string的实际使用长度

end;

end.