Pascal Programming Written by Leung King Yung

Simple Program 1 begin end.

Simple Program 2 program Test; uses wincrt; begin writeln(‘Good Afternoon!’); end.

Simple Program 2 Results:

Reserverd Words begin end program var string if then else for to downto while do repeat until procedure function in These are the common reserved words of pascal program. You cannot use this as a variable name.

Program Title program Test; {This is the program title(you can omit it)} begin {Main Body} end.

Data type These are the common data type of pascal program. TypeExplanation Additional explanation Example integer Whole numbers 3, 104, 0, -9 string String variable(Text) 'Hello World', '456,4' char Character(One character) 'b', 'A', '7' boolean Boolean variable Can only be True or False True, False real Real numbers(Floating point numbers) 4.0, -0.08, 48.6, 2.0E4

Declaring variable program Test; var i : integer; var s : string; var c : char; var b : boolean; var r : real; begin {Main Body} end.

Declaring variable program Test; Uses wincrt; var i : integer; s : string; c : char; b : boolean; r : real; Begin I := 0; Writeln(i); end.

Using Library program Test; uses wincrt; {Wincrt is a common library in turbo pascal for i/o manipulations wincrt.tpu} var i : integer; begin {Main Body} end.

Using Variables program Test; uses wincrt; var i : integer; Begin Readln(i); writeln(i); end.

Using Variables Results:

Using Variables program Test; uses wincrt; var i : integer; j : integer; begin i := 7; j := 3; i := i + j; writeln(i); end.

Using Variables Results:

Comparing VB with Pascal VB: Dim i as integer Pascal: var i : integer; VB: i = 10 Pascal: i := 10; VB: ‘comment Pascal: {Comment}/(*Comment*)

Comparing VB with Pascal VB: Dim j as integer j = 10 If j = 10 then print “J = 10” Else print “J <> 10” End If

Comparing VB with Pascal Pascal: Uses wincrt; var j : integer; begin j := 10; if j = 10 then writeln(‘J = 10’) else writeln(‘J <> 10’); End.

IF…THEN…ELSE program Test; var j : integer; begin j := 10; if j = 10 then writeln(‘J = 10’) {*** No “;”} else writeln(‘J <> 10’); writeln(‘End of program’); end;

IF…THEN…ELSE program Test; var j : integer; begin j := 10; if j = 10 then writeln(‘J = 10’) else writeln(‘J <> 10’); writeln(‘End of program’); end; The whole If-Phrase

Complicated IF…THEN…ELSE if i = 10 then if j = 10 then writeln(‘i = 10 and j = 10’) else writeln(‘i = 10 and j <> 10’) else writeln(‘i <> 10 and j <> 10’); Correct Program

Complicated IF…THEN…ELSE if i = 10 then if j = 10 then writeln(‘i = 10 and j = 10’) else writeln(‘i = 10 and j <> 10’); else writeln(‘i <> 10 and j <> 10’); Wrong semicolon (Syntax Error)

Comment begin {This is a comment} (* This is also a comment*) end.