Generic sequencer tcomparer

Test code file:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls; Type tform1 = Class (tform) memo1: tmemo; memo2: tmemo; example: tbutton; button2: tbutton; button3: tbutton; button4: tbutton; button5: tbutton; button6: example; example: tbutton; button9: tbutton; button10: tbutton; procedure extract (Sender: tobject); Procedure button2click (Sender: tobject); Procedure extract (Sender: tobject ); procedure alert (Sender: tobject); Procedure button10click (Sender: tobject ); end; var form1: tform1; implementation {$ R *. DFM} uses generics. collections, generics. defaults; {required generic units} // construct a dynamic array consisting of 10 integers, and then sort procedure tform1.button1click (Sender: tobject); var arr: array of integer; I: integer; begin {build dynamic array} randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; {display before sorting} memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); {sort} tarray. sort <integer> (ARR); {It can have 1, 2, and 4 parameters. Here only one parameter is used, and others are default parameters }{ display sorting result} memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); end; // tarray. the second parameter of sort is the icomparer <t> type. The default value is tcomparer <t>. defaultprocedure tform1.button2click (Sender: tobject); var arr: array of integer; I: integer; begin randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); {use the default value of the sorter for sorting, which is the same as ignoring this parameter} tarray. sort <integer> (ARR, tcomparer <integer>. default); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); end; // The same as the preceding example. You can use procedure tform1.button3click (Sender: tobject); var arr: array of integer; I: integer; comparer: icomparer <integer>; begin randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); comparer: = tcomparer <integer>. default; tarray. sort <integer> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); end; // tarray. the following two parameters of sort can specify the sorting range: Procedure tform1.button4click (Sender: tobject); var arr: array of integer; I: integer; comparer: icomparer <integer>; begin randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); comparer: = tcomparer <integer>. default; {starting from 1st elements, only three elements are sorted here} tarray. sort <integer> (ARR, comparer, 0, 3); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); end; // If You Want To sort data in reverse order, you can create your own sorters. The following describes how to build and implement a tmycomparer and then call it: type tmycomparer = Class (tcomparer <integer>) public function compare (const left, right: integer): integer; override; end; {tmycomparer} function tmycomparer. compare (const left, right: integer): integer; begin result: = right-left; end; Procedure tform1.button5click (Sender: tobject); var arr: array of integer; I: integer; comparer: tmycomparer; begin randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); comparer: = tmycomparer. create; tarray. sort <integer> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); comparer. free; end; // you can also use tcomparer <t>. the construct method uses a function in the tcomparison format to construct the sequencer. In this way, some simple functions myfunc1 (const left, right: integer): integer; begin result: = right-left; end; procedure tform1.button6click (Sender: tobject); var arr: array of integer; I: integer; comparer: icomparer <integer>; begin randomize; for I: = 0 to 9 do begin setlength (ARR, length (ARR) + 1); arr [I]: = random (10); end; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (inttostr (ARR [I]); comparer: = tcomparer <integer>. construct (myfunc1); tarray. sort <integer> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (inttostr (ARR [I]); end; // If You Want To sort elements of the custom type, you can only use the self-built sorter type tperson = Record Name: string; age: word; end; function myfunc2 (const left, right: tperson): integer; begin result: = left. age-right. age; end; Procedure tform1.button7click (Sender: tobject); var arr: array of tperson; I: integer; comparer: icomparer <tperson>; begin setlength (ARR, 4 ); arr [0]. name: = 'a'; arr [0]. age: = 22; arr [1]. name: = 'bb'; arr [1]. age: = 33; arr [2]. name: = 'cc'; arr [2]. age: = 44; arr [3]. name: = 'dd'; arr [3]. age: = 11; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (format ('% s: % d', [arr [I]. name, arr [I]. age]); comparer: = tcomparer <tperson>. construct (myfunc2); tarray. sort <tperson> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (format ('% s: % d', [arr [I]. name, arr [I]. age]); end; // tstringcomparer. ordinal is an officially implemented string sequencer and can be directly used. // but it seems that there is a problem (Delphi 2010-14.0.3513.24210), and later versions should be able to be changed. procedure tform1.button8click (Sender: tobject); var arr: array of string; I: integer; begin setlength (ARR, 4); arr [0]: = '2016 '; arr [1]: = '000000'; arr [2]: = 'bbb '; arr [3]: = 'aaa'; memo1.clear; for I: = 0 to length (ARR)-1 do memo1.lines. add (ARR [I]); tarray. sort <string> (ARR, tstringcomparer. ordinal); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (ARR [I]); end; // The following is the sort function mycomparerfunc (const S1, S2: string): integer; begin result: = comparetext (S2, S1); // result: =-comparetext (S1, S2); {or so} end; Procedure tform1.button9click (Sender: tobject); var arr: array of string; I: integer; comparer: icomparer <string>; begin memo1.clear; memo1.lines. commatext: = '11, 33,22, AAA, CCC, BBB '; setlength (ARR, memo1.lines. count); for I: = 0 to length (ARR)-1 do arr [I]: = memo1.lines [I]; comparer: = tcomparer <string>. construct (mycomparerfunc); tarray. sort <string> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (ARR [I]); end; // You Can abbreviated the previous program as procedure tform1.button10click (Sender: tobject); var arr: array of string; I: integer; comparer: icomparer <string>; begin memo1.clear; memo1.lines. commatext: = '11, 33,22, AAA, CCC, BBB '; setlength (ARR, memo1.lines. count); for I: = 0 to length (ARR)-1 do arr [I]: = memo1.lines [I]; comparer: = tcomparer <string>. construct (function (const S1, S2: string): integer begin result: = comparetext (S2, S1); End); tarray. sort <string> (ARR, comparer); memo2.clear; for I: = 0 to length (ARR)-1 do memo2.lines. add (ARR [I]); end.
 

Test the Form file (the reason why the Form file is attached is to facilitate the test again ):

object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 321  ClientWidth = 318  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  PixelsPerInch = 96  TextHeight = 13  object Memo1: TMemo    Left = 0    Top = 0    Width = 89    Height = 321    Align = alLeft    Lines.Strings = (      'Memo1')    TabOrder = 0    ExplicitHeight = 299  end  object Button1: TButton    Left = 120    Top = 8    Width = 75    Height = 25    Caption = 'Button1'    TabOrder = 1    OnClick = Button1Click  end  object Button2: TButton    Left = 120    Top = 39    Width = 75    Height = 25    Caption = 'Button2'    TabOrder = 2    OnClick = Button2Click  end  object Button3: TButton    Left = 120    Top = 70    Width = 75    Height = 25    Caption = 'Button3'    TabOrder = 3    OnClick = Button3Click  end  object Memo2: TMemo    Left = 219    Top = 0    Width = 99    Height = 321    Align = alRight    Lines.Strings = (      'Memo2')    TabOrder = 4    ExplicitHeight = 299  end  object Button4: TButton    Left = 120    Top = 101    Width = 75    Height = 25    Caption = 'Button4'    TabOrder = 5    OnClick = Button4Click  end  object Button5: TButton    Left = 120    Top = 132    Width = 75    Height = 25    Caption = 'Button5'    TabOrder = 6    OnClick = Button5Click  end  object Button6: TButton    Left = 120    Top = 163    Width = 75    Height = 25    Caption = 'Button6'    TabOrder = 7    OnClick = Button6Click  end  object Button7: TButton    Left = 120    Top = 194    Width = 75    Height = 25    Caption = 'Button7'    TabOrder = 8    OnClick = Button7Click  end  object Button8: TButton    Left = 120    Top = 225    Width = 75    Height = 25    Caption = 'Button8'    TabOrder = 9    OnClick = Button8Click  end  object Button9: TButton    Left = 120    Top = 256    Width = 75    Height = 25    Caption = 'Button9'    TabOrder = 10    OnClick = Button9Click  end  object Button10: TButton    Left = 120    Top = 287    Width = 75    Height = 25    Caption = 'Button10'    TabOrder = 11    OnClick = Button10Click  endend