So far, you have learned how to use an 'if statement'. But in some cases the 'case statement' is preferred to the if statement because it reduces some unnecessary code but the same meaning is retained. The case statement is very similar to the if statement, except in that the it does not accept literal conditional expressions (i.e.: strings) but surprisingly enough, it allows single character conditional expressions. Here is how it works:
Case {variable of type: integer or character ONLY} of
{input statement- within inverted commas if of type char} : {code..}
{input statement- within inverted commas if of type char} : {code..}
...
End; {End Case}
Now you should note the difference and the intelligent use of the case statement over the if statement.
The Program is written using the if statement:
Program Program1a_Lesson5;
Uses Crt;
Label Return; {used respectively with the
goto statement; beware of it}
Var SEL : Integer;
YN : Char;
Begin
Return: Clrscr;
Writeln('[1].PLAY GAME');
WRITELN('[2].LOAD GAME');
WRITELN('[3].MULTIPLAYER');
WRITELN('[4].EXIT GAME');
Writeln('note: Do note press anything except');
Writeln('numbers; otherwise an error occurs!');
Readln(SEL);
If SEL = 1 then
Begin
Writeln('Are you able to create a game');
Writeln('of yourself using pascal??');
Delay(2000);
Goto Return;
End;
If SEL = 2 then
Begin
Writeln('Ahhh... no saved games');
Delay(2000);
Goto Return;
End;
If SEL = 3 then
Begin
Writeln('networking or 2 players?');
Delay(2000);
Goto Return;
End;
If SEL = 4 then
Begin
Writeln('Exit?');
YN := Readkey;
If YN = 'y' then
Begin
Writeln('Nooooooooooooo...');
Delay(1000);
Halt; {EXIT PROGRAM}
End;
If YN = 'n' then
Goto Return;
End;
End.
|
Now,
the next program is written using the case statement and the output
is almost the same.
Program Program1b_Lesson5;
Uses Crt;
Label Return; {use of the goto statement
is not recommended..avoid it}
Var SEL : Integer;
YN : Char;
Begin
Return:Clrscr;
Writeln('[1].PLAY GAME');
WRITELN('[2].LOAD GAME');
WRITELN('[3].MULTIPLAYER');
WRITELN('[4].EXIT GAME');
Writeln('note: Do note press anything except');
Writeln('numbers; otherwise an error occurs!');
Readln(SEL);
Case SEL of
1 : Begin
Writeln('Are you able to create');
Writeln('a game of yourself using pascal??');
Delay(2000);
Goto Return;
End;
2 : Begin
Writeln('Ahhh... no saved games');
Delay(2000);
Goto Return;
End;
3 : Begin
Writeln('networking or 2 players?');
Delay(2000);
Goto Return;
End;
4 : Begin
Writeln('Exit?');
YN := Readkey;
Case YN of {a sort of a nested case statement}
'y' : Begin
Writeln('Nooooooooooooo...');
Delay(1000);
Halt;
End;
'n' : Goto Return;
End;{End Case2}
End;{Close Conditional Expression 4}
End; {End Case1}
End. |
| This source code had a syntax error and is now corrected (Vaar changed to Var) |
|
