program HelloWorld; uses SysUtils; begin Writeln('Hello Pascal!'); Readln; end. 

program 程序名; uses 单元列表; const 常量定义; var 变量定义; procedure 过程; function 函数; begin 代码; end.

program, uses, begin, end, var, const, type if, then, else, case, for, to, downto, while, repeat, until break, continue, exit procedure, function, result and, or, not, xor, in, is nil, true, false integer, string, boolean, char, real, double array, record, class try, except, finally, raise

absolute, asm, assembler, cdecl, export, external, far, forward, inline, library, overload, override, private, protected, public, published, static, virtual

var age: Integer; name: string; price: Double; isOK: Boolean; c: Char; 

age := 18; name := '张三'; price := 19.9; isOK := True;

const VERSION = '1.0.0'; MAX_COUNT = 100;

+ - * / div mod

a := 10 div 3; b := 10 mod 3; 

= <> > < >= <=

and or not

if age >= 18 then Writeln('成年') else Writeln('未成年');

case score of 90..100: Writeln('优秀'); 60..89: Writeln('及格'); else Writeln('不及格'); end;

for i := 1 to 10 do Writeln(i);

i := 1; while i <= 5 do begin Writeln(i); i := i + 1; end;

repeat Writeln(i); i := i + 1; until i > 5;

for i := 1 to 10 do begin if i = 3 then Continue; if i = 6 then Break; Writeln(i); end;

procedure SayHello(msg: string); begin Writeln('你好：', msg); end;

function Add(a, b: Integer): Integer; begin Result := a + b; end;

var s: string; len: Integer; begin s := 'abc123'; len := Length(s); s := UpperCase(s); s := LowerCase(s); s := Copy(s, 1, 3); s := IntToStr(123); i := StrToInt('123'); end;

var arr: array[0..4] of Integer; i: Integer; begin arr[0] := 10; for i := 0 to 4 do Writeln(arr[i]); end;

type TUser = record Name: string; Age: Integer; end; var user: TUser; begin user.Name := '李四'; user.Age := 20; end;

try i := StrToInt('abc'); except on E: Exception do Writeln('错误：', E.Message); end;

var name: string; begin Write('请输入名字：'); Readln(name); Writeln('你好，', name); end;

program StudentManager; uses SysUtils; const MAX_STUDENT = 3; type TStudent = record Name: string; Score: Double; end; var Students: array[0..MAX_STUDENT-1] of TStudent; i: Integer; avg: Double; choice: Integer; function GetAvgScore: Double; var sum: Double; j: Integer; begin sum := 0; for j := 0 to MAX_STUDENT-1 do sum := sum + Students[j].Score; Result := sum / MAX_STUDENT; end; begin Writeln('=== 学生成绩管理 ==='); for i := 0 to MAX_STUDENT-1 do begin Write('姓名：'); Readln(Students[i].Name); Write('分数：'); Readln(Students[i].Score); end; repeat Writeln(#10#13'1=查看 2=平均分 3=退出'); try Readln(choice); except choice := 0; end; case choice of 1: begin Writeln('--- 学生列表 ---'); for i := 0 to MAX_STUDENT-1 do Writeln(Students[i].Name, ' ', Students[i].Score); end; 2: begin avg := GetAvgScore; Writeln('平均分：', avg:0:2); end; 3: Writeln('退出'); else Writeln('输入错误'); end; until choice = 3; Writeln('结束'); Readln; end.