Generic sequencer tcomparer

TestCodeFile:
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Unit unit1;

Interface

Uses
Windows, messages, sysutils, variants, classes, graphics, controls, forms,
Dialogs, stdctrls;

Type
Tform1 = Class (tform)
Memo1: tmemo;
Memo2: tmemo;
Button1: tbutton;
Button2: tbutton;
Button3: tbutton;
Button4: tbutton;
Button5: tbutton;
Button6: tbutton;
Button7: tbutton;
Button8: tbutton;
Button9: tbutton;
Button10: tbutton;
Procedure button1click (Sender: tobject );
Procedure button2click (Sender: tobject );
Procedure button3click (Sender: tobject );
Procedure button4click (Sender: tobject );
Procedure button5click (Sender: tobject );
Procedure button6click (Sender: tobject );
Procedure button7click (Sender: tobject );
Procedure button8click (Sender: tobject );
Procedure button9click (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
{Construct a 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]);

{Sorting}
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;

// The second parameter of tarray. sort is of the icomparer <t> type. The default value is tcomparer <t>. default.
Procedure 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]);

{The default value of the sorter is used 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 preceding two examples have been modified.
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;

// The last two parameters of tarray. 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;
{Here, we specify to order only three elements starting from 1st elements}
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 sequencer. 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 the tcomparer <t>. Construct method to construct a sequencer using a function in the tcomparison format.
Function 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]: = '000000 ';
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 describes how to sort string arrays.
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 set the previousProgramAbbreviated:
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;

End.