[SOLVED] Exit code 201 Snake Game

[DiCri]

I don't know why... I only know that it works only on Turbo Pascal but i've choosed Free Pascal 'cause it has more functions and a good compiler.. Here is the source code of the Snake game.. Simple but it tells exit code 201 at the end of the procedure createscore.

Code: Pascal  [Select][+][-]

1. program snake;
2. uses crt;
3. var
4.         x,y:array[1..1000] of integer;
5.         xs,ys:integer;
6.         input:char;
7.         i,j:integer;
8. procedure createscore;
9.         begin
10.  
11.                 randomize;
12.                 xs:=0;
13.                 ys:=0;
14.                 xs:=random(79)+1;
15.                 ys:=random(23)+1;
16.                 gotoxy(xs,ys);
17.                 write('.');
18.  
19.  
20.         end;
21. procedure incscore;
22.         begin
23.                         if (x[1]=xs) and (y[1]=ys) then begin
24.                                 gotoxy(xs,ys);
25.                                 write(' ');
26.                                 j:=j+1;
27.                                 xs:=0;
28.                                 ys:=0;
29.                                 gotoxy(1,1);
30.                                 writeln(i,',',j,',',xs,',',ys,',',x[1],',',y[1]);
31.                                 input:=readkey;
32.                                 createscore;
33.                                 end;
34.         end;
35.  
36. procedure checkdie;
37.         begin
38.               {  for i:=2 to j do begin
39.                         if (x[1]=x[i]) and (y[1]=y[i]) then
40.                                 input:='q';
41.                         end;}
42.                 end;
43. begin
44.         clrscr;
45.         randomize;
46.         cursoroff;
47.         createscore;
48.         for i:=1 to 3 do begin
49.         x[i]:=random(80)+1;
50.         y[i]:=random(23)+1;
51.         end;
52.         gotoxy(x[1],y[1]);
53.         write('O');
54.         j:=3;
55.         repeat
56.                 if keypressed then input:=readkey;
57.                         for i:=1 to j do
58.                                 begin
59.                                 gotoxy(x[i],y[i]);
60.                                 write(' ');
61.                                 end;
62.                         for i:=j downto 2 do
63.                                 begin
64.                                         x[i]:=x[i-1];
65.                                         y[i]:=y[i-1];
66.                                 end;
67.                         if input='w' then y[1]:=y[1]-1;
68.                         if input='s' then y[1]:=y[1]+1;
69.                         if input='a' then x[1]:=x[1]-1;
70.                         if input='d' then x[1]:=x[1]+1;
71.                         for i:=1 to j do
72.                                 begin
73.                                 gotoxy(x[i],y[i]);
74.                                 write('O');
75.                                 end;
76.                         incscore;
77.  
78.  
79.                         delay(50);
80.                 until input='q';
81.  
82. end.
83.  
84.  

Please answer me! Thanks

[skalogryz]

are you running it on Windows?,
-> if yes, are you compiling it with Lazarus,
---> if yes, check your Project Options -> Config and Target. "Win32 Gui application" must be UNCHECKED.
---> or
---> or you can add the following {$APPTYPE} reference into your source code, like this

Code: Pascal  [Select][+][-]

1. program snake;
2. {APPTYPE CONSOLE}
3. uses crt;
4. ..
5.  

[Bart]

For me it crashes with a range check error on this line:

Code: [Select]

                                gotoxy(x[i],y[i]);

At that point  i = 1, j = 3, x = 7, y = 256

The screen looks like:

Code: [Select]



       O
       OO
       OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
 OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
 OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
 OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
 OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
 OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   O
OO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO   OOO
   OOO   OOO 

I started the program, then pressed "s" once and let it run it's course.

Bart

[DiCri]

I am using normal Free Pascal and not Lazarus

[rvk]

Here is the source code of the Snake game.. Simple but it tells exit code 217 at the end of the procedure createscore.

Not really a clear question. In the question you say exit code 201 and in the text you mention exit code 217. Which is it?

Also... you don't say WHEN you get this error. When I run this, I don't get an exit code until I press w and the snake comes to the top of the screen. In that case I get a exit code 201.

You don't check for getting to the edge of the screen so if the snake gets to the edge you either get an exit code 201 or the program gives lots of 000.

Build in some checks for this and your program should run fine.

[skalogryz]

I am using normal Free Pascal and not Lazarus

sure. but please try adding {$APPTYPE CONSOLE} and let us know if it fixed the issue.

[DiCri]

I don't want to fix when snake reaches limits of screen.. i know how to do it but it is not the problem i told. When running the game, there is a dot (must be the apple) but when the snake takes it, it tells exit code 201 on free pascal.. Trying to put {$APPTYPE CONSOLE}. I'm italian so i'm wrong with some English words

[skalogryz]

the problem is that your x,y arrays are uninitialized.

Thus then you take an apple and you j increases.

The next "clearing" loop

Code: [Select]

    for i:=1 to j do  begin
      gotoxy(x[i],y[i]);
      write(' ');
    end;
Reads x[ i ], y[ i ] from the new "j" variable.
Again, since x and y are not initialized  the value x[ i ] or y[ i ] can be over 255 (which is the limit for gotoxy() procedure), which is causing 201.

You can fix the issue by initializing x,y

Code: Pascal  [Select][+][-]

1.  
2. begin
3.   clrscr;
4.   randomize;
5.   for i:=1 to 1000 do begin
6.     x[i]:=1; y[i]:=1;
7.   end;
8.   ...
9.  

[Bart]

Initializing x and y (which can be done faster using FillChar b.t.w.) does not prevent the range check error in the line I previously mentioned.

Make both x and y array[1..1000] of Byte and you wil see where it happens.

Bart

[rvk]

Reads x[ i ], y[ i ] from the new "j" variable.
Again, since x and y are not initialized  the value x[ i ] or y[ i ] can be over 255 (which is the limit for gotoxy() procedure), which is causing 201.

Close The x and y array are initialized with all zeros. This is why the x[j] crashes on gotoxy because you can't go to position 0.

Initializing both arrays to 1 does fix the 201 after hitting the apple.

I would also build in the following lines to make sure the snakes crosses over the edges without triggering a 201 exit.

Code: Pascal  [Select][+][-]

1.     if (y[1] = 26) then y[1] := 1
2.     else if (y[1] = 0) then y[1] := 25;
3.     if (x[1] = 80) then x[1] := 1
4.     else if (x[1] = 0) then x[1] := 80;
5.  

It would also fix the error Bart mentioned.

[skalogryz]

(which can be done faster using FillChar b.t.w.)

well... FillChar didn't exist at TP

[Bart]

well... FillChar didn't exist at TP

Are you sure?
I can remember using FillChar in ancient programs of mine.

See e.g. http://putka.upm.si/langref/turboPascal/055E.html

Anyhow FillChar doesn't do what I intended on an array of integer, stupid me.

Bart

[Bart]

There's another annoying bit: if the program crashes, the console has no cursor anymore.

Bart

[rvk]

There's another annoying bit: if the program crashes, the console has no cursor anymore.

The program doesn't even need to crash for that. Just pressing q exists the program but the cursor is never reset to the correct default

[Bart]

The program doesn't even need to crash for that. Just pressing q exists the program but the cursor is never reset to the correct default

Even better 

Bart