delphi 使用泛型的 TArray 从动态数组中查找指定元素

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}

uses Generics.Collections; {引用泛型单元}

{从字符串数组中查找}

procedure TForm1.Button1Click(Sender: TObject);

var

arr: array of string;

num: Integer;

begin

{构建动态数组}

SetLength(arr, 5);

arr[0] := 'aaa';

arr[1] := 'bbb';

arr[2] := 'ccc';

arr[3] := 'ddd';

arr[4] := 'eee';

{查找}

TArray.BinarySearch(arr, 'ddd', num);

{显示查找结果}

if num < Length(arr) then {如果 num = Length(arr) 就是没找到}

ShowMessage(IntToStr(num)); {3}

end;

{从整数数组中查找}

procedure TForm1.Button2Click(Sender: TObject);

var

arr: array of Integer;

num: Integer;

begin

{构建动态数组}

SetLength(arr, 5);

arr[0] := 11;

arr[1] := 22;

arr[2] := 33;

arr[3] := 44;

arr[4] := 55;

{查找}

TArray.BinarySearch(arr, 44, num);

{显示查找结果}

if num < Length(arr) then {如果 num = Length(arr) 就是没找到}

ShowMessage(IntToStr(num)); {3}

end;

end.

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