我写了个最笨的方法,呵呵function TForm1.CheckStr(const S: string): Boolean; var i:Integer; a,b,c:Boolean; begin Result:=False; a:=False; b:=False; c:=False; for i:=0 to Length(s) do begin if S[i] in ['0'..'9'] then begin a:=True; end; if S[i] in ['a'..'z'] then begin b:=True; end; if S[i] in ['A'..'Z'] then begin c:=True; end; end; if (a and b) or (a and c) then Result:=True; end;
那你可以一个字符一个字符去判断 STR[I]是不是在 ‘a’-'z' 'A'-'Z' '0'-'9' 其他的就不是 函数基本可以写成 function CheckStr:Boolean var i:integer; begin result := True; for i := 1 to Length(str) do begin if not (str[i] in['a'..'z']) then if not (str[i] in ['A'..'Z']then if not (Str[i] in ['0'..'9'] then begin result := false; break; end end; end;
str='dfefe21erQEcccc'; j:= 0; K:= 0; for i:= 1 to length(str) - 1 do begin str1:= copy(str,i,1); try strtoint(str1); k:= K + 1; except j:= j+ 1; end; end; //k为数字个数,j为字母个数 if (k = 0) or (j = 0) then showmessage('不是字母和数字组成的字符串!'); end;
function CheckStr:Boolean var i:integer; begin result := True; for i := 1 to Length(str) do begin if not (str[i] in['a'..'z']) then if not (str[i] in ['A'..'Z']then if not (Str[i] in ['0'..'9'] then begin result := false; break; end end; end;
function IsAlphanumeric(const S: string): Boolean; const Alphanumerics = ['A'..'Z', 'a'..'z', '0'..'9']; var i : Integer; begin Result := False; for i:=1 to Length(S)do if(not(S[i]in Alphanumerics))then Exit; Result := True; end;
unit Unit2;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm2 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end;var Form2: TForm2;implementation{$R *.dfm}function isCheck(vStr:String):Boolean; var vCheck : byte; vChar : Pchar; begin Result := false; vChar := pchar(vStr); vCheck := 0; while vChar^ <> #0 do begin if vChar^ in ['0'..'9'] then begin if vCheck =2 then begin Result := True; break; end else vCheck := 1; end; if vChar^ in ['a'..'z','A'..'Z'] then begin if vCheck = 1 then begin result := true; break; end else vCheck := 2; end; inc(vChar); end; end; procedure TForm2.Button1Click(Sender: TObject); var Str : String; begin str :='dfefeerQEcccc'; if isCheck(str) then showMessage('人老了') else showMessage('還未老');end;end. 亂來的。呵呵
随便写了一个:procedure TForm1.Button1Click(Sender: TObject); var i:integer; str:string; sum:string; begin if edit1.Text='' then ShowMessage('请输入字符串') else begin sum:=''; str:=Edit1.Text; for i:=1 to Length(str)do begin if str[i] in ['a'..'z','A'..'Z','0'..'9']then sum:=sum+str[i] else begin ShowMessage('No'); Exit; end; end; ShowMessage(sum); end; end;
var
i:Integer;
a,b,c:Boolean;
begin
Result:=False;
a:=False;
b:=False;
c:=False;
for i:=0 to Length(s) do
begin
if S[i] in ['0'..'9'] then
begin
a:=True;
end;
if S[i] in ['a'..'z'] then
begin
b:=True;
end;
if S[i] in ['A'..'Z'] then
begin
c:=True;
end;
end;
if (a and b) or (a and c) then Result:=True;
end;
STR[I]是不是在
‘a’-'z'
'A'-'Z'
'0'-'9'
其他的就不是
函数基本可以写成
function CheckStr:Boolean
var
i:integer;
begin
result := True;
for i := 1 to Length(str) do
begin
if not (str[i] in['a'..'z']) then
if not (str[i] in ['A'..'Z']then
if not (Str[i] in ['0'..'9'] then
begin
result := false;
break;
end end;
end;
str='dfefe21erQEcccc';
j:= 0;
K:= 0;
for i:= 1 to length(str) - 1 do
begin
str1:= copy(str,i,1);
try
strtoint(str1);
k:= K + 1;
except
j:= j+ 1;
end;
end;
//k为数字个数,j为字母个数
if (k = 0) or (j = 0) then
showmessage('不是字母和数字组成的字符串!');
end;
function CheckStr:Boolean
var
i:integer;
begin
result := True;
for i := 1 to Length(str) do
begin
if not (str[i] in['a'..'z']) then
if not (str[i] in ['A'..'Z']then
if not (Str[i] in ['0'..'9'] then
begin
result := false;
break;
end end;
end;
function IsAlphanumeric(const S: string): Boolean;
const
Alphanumerics = ['A'..'Z', 'a'..'z', '0'..'9'];
var
i : Integer;
begin
Result := False;
for i:=1 to Length(S)do
if(not(S[i]in Alphanumerics))then Exit;
Result := True;
end;
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;type
TForm2 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;var
Form2: TForm2;implementation{$R *.dfm}function isCheck(vStr:String):Boolean;
var
vCheck : byte;
vChar : Pchar;
begin
Result := false;
vChar := pchar(vStr);
vCheck := 0;
while vChar^ <> #0 do
begin
if vChar^ in ['0'..'9'] then
begin
if vCheck =2 then begin
Result := True;
break;
end else vCheck := 1;
end; if vChar^ in ['a'..'z','A'..'Z'] then
begin
if vCheck = 1 then begin
result := true;
break;
end else vCheck := 2;
end;
inc(vChar);
end;
end;
procedure TForm2.Button1Click(Sender: TObject);
var
Str : String;
begin
str :='dfefeerQEcccc';
if isCheck(str) then showMessage('人老了') else showMessage('還未老');end;end.
亂來的。呵呵
var
i:integer;
str:string;
sum:string;
begin
if edit1.Text='' then
ShowMessage('请输入字符串')
else
begin
sum:='';
str:=Edit1.Text;
for i:=1 to Length(str)do
begin
if str[i] in ['a'..'z','A'..'Z','0'..'9']then
sum:=sum+str[i]
else
begin
ShowMessage('No');
Exit;
end;
end;
ShowMessage(sum);
end;
end;