Isletter, Isupper, Islower, IsDigit, Isnumber
IsLetter: {是否是个字母; 范围 A..Z 与 a..z}
IsUpper: {是否是个大写字母; 范围 A..Z}
IsLower: {是否是个小写字母; 范围 a..z}
IsDigit: {是否是个十进制数字; 范围 0..9}
IsNumber: {是否是个数字符号; 范围包括 0..9, 还有 ASCII 码中的 178、179、185、188、189、190 等}
Test code:
Unit Unit1;
Interface
Uses
Windows, Messages, sysutils, variants, Classes, Graphics, Controls, Forms,
Dialogs, Stdctrls;
Type
TForm1 = Class (Tform)
Button1:tbutton;
Button2:tbutton;
Button3:tbutton;
Button4:tbutton;
Button5:tbutton;
Procedure Button1Click (Sender:tobject);
Procedure Button2click (Sender:tobject);
Procedure Button3click (Sender:tobject);
Procedure Button4click (Sender:tobject);
Procedure Button5click (Sender:tobject);
End
Var
Form1:tform1;
Implementation
{$R *.DFM}
Uses Character;
{isletter: Whether it is a letter}
Procedure Tform1.button1click (Sender:tobject);
Var
B1,b2,b3:boolean;
Begin
B1: = Isletter (' A '); Is
B2: = Isletter (' a '); Is
B3: = Isletter (' 9 '); Whether
SHOWMESSAGEFMT ('%s,%s,%s ', [Booltostr (B1,true), Booltostr (B2,true), Booltostr (b3,true)]);
{True,true,false}
B1: = Isletter (' D2009 ', 1);
B2: = Isletter (' D2009 ', 2);
SHOWMESSAGEFMT ('%s,%s ', [Booltostr (B1,true), Booltostr (b2,true)]);
{True,false}
End
{isupper: is a capital letter}
Procedure Tform1.button2click (Sender:tobject);
Var
B1,b2,b3:boolean;
Begin
B1: = Isupper (' A '); Is
B2: = Isupper (' a '); Whether
B3: = Isupper (' 9 '); Whether
SHOWMESSAGEFMT ('%s,%s,%s ', [Booltostr (B1,true), Booltostr (B2,true), Booltostr (b3,true)]);
{True,false,false}
B1: = Isupper (' Delphi ', 1);
B2: = Isupper (' Delphi ', 2);
SHOWMESSAGEFMT ('%s,%s ', [Booltostr (B1,true), Booltostr (b2,true)]);
{True,false}
End
{islower: is a lowercase letter}
Procedure Tform1.button3click (Sender:tobject);
Var
B1,b2,b3:boolean;
Begin
B1: = Islower (' A '); Whether
B2: = Islower (' a '); Is
B3: = Islower (' 9 '); Whether
SHOWMESSAGEFMT ('%s,%s,%s ', [Booltostr (B1,true), Booltostr (B2,true), Booltostr (b3,true)]);
{False,true,false}
B1: = Islower (' Delphi ', 1);
B2: = Islower (' Delphi ', 2);
SHOWMESSAGEFMT ('%s,%s ', [Booltostr (B1,true), Booltostr (b2,true)]);
{False,true}
End
{isdigit: is a decimal digit}
Procedure Tform1.button4click (Sender:tobject);
Var
B1,b2,b3:boolean;
Begin
B1: = IsDigit (' A '); Whether
B2: = IsDigit (' ½ '); Whether
B3: = isdigit (' 9 '); Is
SHOWMESSAGEFMT ('%s,%s,%s ', [Booltostr (B1,true), Booltostr (B2,true), Booltostr (b3,true)]);
{False,false,true}
B1: = IsDigit (' D2009 ', 1);
B2: = IsDigit (' D2009 ', 2);
SHOWMESSAGEFMT ('%s,%s ', [Booltostr (B1,true), Booltostr (b2,true)]);
{False,true}
End
{isnumber: is a numeric symbol}
Procedure Tform1.button5click (Sender:tobject);
Var
B1,b2,b3:boolean;
Begin
B1: = Isnumber (' A '); Is
B2: = Isnumber (' ½ '); Is
B3: = Isnumber (' 9 '); Whether
SHOWMESSAGEFMT ('%s,%s,%s ', [Booltostr (B1,true), Booltostr (B2,true), Booltostr (b3,true)]);
{False,true,true}
B1: = Isnumber (' 123¹²³¼½¾ ', 1);
B2: = Isnumber (' 123¹²³¼½¾ ', 4); {All 9 characters here are compound}
SHOWMESSAGEFMT ('%s,%s ', [Booltostr (B1,true), Booltostr (b2,true)]);
{True,true}
End
End.