why

Is the text "The drawing is:" being printed to the screen?

Is your commandarray correct? Check this in the debugger.

Originally posted by wargis
no its not showing that text.
it seems correct, same data type, declaration. dunno whats wrong. im not fimiliar with the debuigger, i get all these symbols i can't understand.:blush:

[edit]; typo

You can't possibly learn to program without being familiar with your debugger. That should be your highest priority. It will let you see line by line what your program is doing, how it got to where it is, current variable values, etc. Absolutely indispensible.

im only a beginner, not familiar with debug.
do you mean (in c++) you go build > start debug > go?
because thats all i know, then what?

anyone please? its stumped me, can anyone tell me why/where the problem is?

hmm ok, i done what you suggested. but it comes with this error after ive inserted the breakpoint and ran the program through the debugger.
"Unhandled exception in comp.exe (NTDLL.DLL): 0xc0000005: Access Violation"

??

Originally posted by wargis
im only a beginner, not familiar with debug.
do you mean (in c++) you go build > start debug > go?
because thats all i know, then what?

No. Go to menu->Build->Set Active Configuration. Select the Debug one here and build the project and once the exe is built, hit F5

And indeed, if you don't know how to use the debugger, then you should definitely take the time to learn it.
You can't program without a debugger!

for(j=0; j>2; ++j)
commandarray[k][j] =0;

does not seem correct. Maybe for(j=0;j < 2; j++)??

my god, thanks fellas, silly errors that were overlooked.
now theres 2 things wrong, it won't turn left, right or go down. and say, i put pen down, and after that i input 5,5 (first 5 refers to move forward and the 2nd digit (which is a 5 in this case refers to how many spaces to move) it will move 1 short of that, in my case 4 spaces.??
heres the code agian, wheres the problem?

//Header Files
#include <iostream.h>
#include <stdlib.h>

//Global Declarations
const int MAXCOMMANDS = 100;
const int SIZE = 20;
char ans;
char ignore=',';

int j;
int x;
int y;
int direction =0;
int commandarray[MAXCOMMANDS][2];// ={0};
int floor[SIZE][SIZE];// ={0};

//Function Prototypes
int turnright(int);
int turnleft(int) ;
void getcommands(int [][2]);
int movepen(bool&, int [][SIZE], int, int, int&, int&);
void printarray(int [][SIZE]);

//Main program
void main()
{

int command =0;


bool pendown = false;

do
{
//Initialize variables each time
for(int j =0; j<SIZE; ++j)
{
for(int k=0; k<SIZE; ++k)
floor[j][k]=0;
}
for(int k=0; k<100; ++k)
{
for(int j=0; j>2; ++j)
commandarray[k][j] =0;
}
system("cls");
int counter =0;

command =0;
int distance =0;
direction =0;
counter =0;
pendown =false;
int a=0;
int b=0;
system("cls");

getcommands(commandarray);

command = commandarray[counter][0];
while (command !=9)
{
switch (command)
{
case 1: pendown = false;
// cout << "The pen is up";
break;

case 2: pendown = true;
// cout << "The pen is down";
break;

case 3: direction = turnright(direction);
// cout << x<<","<<y;
break;

case 4: direction = turnleft(direction);
// cout << x<<","<< y;
break;
case 5: distance = commandarray[counter][1];
movepen(pendown, floor, direction, distance, a, b);
break;
case 6:
// cout<< "The drawing is:\n\n" ;
printarray(floor);
break;

}
++counter;
command =commandarray[counter][0];
}

cout<<endl<<"Would you like to redraw?";
cin>>ans;
}
while ((ans=='y')||(ans=='Y'));
return;
}

//Defintion of right turn on grid
int turnright(int direction)
{
if(direction==3)
direction =0;
else;
++direction;
return (direction);
}

//Defintion of turn on grid
int turnleft(int direction)
{
if(direction==0)
direction =3;
else;
--direction;
return(direction);
}

//Reads input given
void getcommands( int commandarray[][2] )
{
// int y;
// int entry;
int distance;
int i=0;
int command=0;
cout<<"Please Enter command: "<<endl;


cout <<"\t <<Command List\n\n";
cout <<"\t <<0 : Read from external file\n";
cout <<"\t <<1 : Pen Up\n";
cout <<"\t <<2 : Pen Down\n";
cout <<"\t <<3 : Turn Right\n";
cout <<"\t <<4 : Turn Left\n";
cout <<"\t <<5,x : Move forward x spaces\n";
cout <<"\t <<6 : Print Drawing\n";
cout <<"\t <<9 : End Commands (sentinel)\n\n\n";

do
{
cin>>command;
//cout<<endl;
commandarray[j][0]=command;
if (command==5)
{
cin>>ignore;
cin>>distance;
commandarray[j][1]=distance;
}
++j;

}
while((command !=9) && (i < MAXCOMMANDS));

}
//Moves the pen according to commands given
int movepen( bool &pendown, int floor [][SIZE], int direction, int distance, int &a, int &b)
{

int counter = 0;

switch(direction)

{
case 0: //Right movement
for(counter=0; counter <distance; ++counter)
{
if (pendown==true)
floor[a][b]=1;
else
floor[a][b]=0;
++b;
}
break;


case 1: //Down movement
for(counter=0; counter <distance; ++counter)
{
if (pendown==true)
floor[a][b]=1;
else
floor[a][b]=0;
++b;
}
break;

case 2: //Left movement
for(counter=0; counter <distance; ++counter)
{
if (pendown==true)
floor[a][b]=1;
else
floor[a][b]=0;
--b;
}
break;

case 3: //Up movement
for(counter=0; counter <distance; ++counter)
{
if (pendown==true)
floor[a][b]=1;
else
floor[a][b]=0;
--b;
}
break;
}
return(pendown, a, b);
}
//End of movePen

// Print out the array with desired commands
void printarray(int floor[][SIZE])
{
for (int i=0; i<SIZE; ++i)
{
for (int j=1; j<SIZE; ++j)
{
if (floor[i][j]==0)
cout<<" ";
else
cout<<"*";
}
cout<< endl;
}
return;
}

hi paul, yes im using microsoft visual c++ 6.0, what do you mean there is no output, as in nothing is being plotted by the turnleft/right functions? but it's incrementing/decrementing and returning the final direction, or do i have to cout ++--

hmmm, still not turning left/right. ive tried adding some outputs, modified a bit, but nothing.

yes, iv tried, this yellow arrow runs through the program step-by step.
still cant find it...
:ehh:

the problemm that is

You never clear out the floor array before you input new data. All you're doing now is checking if the answer is 'y' or 'Y' -- you are not doing anything else. You need to reset the floor matrix to spaces.

With proper unit testing, you would not have encountered this problem, but as I mentioned, you made the mistake that a lot of beginners make, and that is to write the whole program first. The trouble that I see is that you will encounter more and more problems ("when I now do this, this doesn't work", etc.), all stemming from not testing the various components first and building the program up this way.

Regards,

Paul McKenzie