Thread: 2D array project help

char table;
char booth;
char smoketable;
char smokebooth;

Those should be local variables, in the 'main' function.

[quote]

// Fill the array with O's to show all seats are empty

for(I=0; I<=24; I++)
{for (J=0; J<= 3; J++)
{table[I][J] = 'O';
}
}

for(I=0; I<=9; I++)
{for (J=0; J<= 3; J++)
{booth[I][J] = 'O';
}
}

for(I=0; I<=24; I++)
{for (J=0; J<= 3; J++)
{smoketable[I][J] = 'O';
}
}

for(I=0; I<=9; I++)
{for (J=0; J<= 3; J++)
{smokebooth[I][J] = 'O';
}
}
[/code]

All of this code is invalid. None of it is contained in a function. You cannot have global code like this. You can declare global variables, but you cannot have global code blocks, they must be contained in a function.

Additionally, you have not declared 'smokebooth', or any of the other arrays at this time.

void main(void)
{

This is wrong. 'main' ALWAYS returns an 'int'. Thus, at the end of your 'main' block, you ad the following:

return 0; //or whatever integer you wish to return. zero is fine.

case 1:
num1 = 1 && num2 = 1;
table(); //would this be calling the table function?

case2:

The line 'num1 = 1 && num2 = 1' is valid C code, and, luckily for you, you end up with the result you expect, but not for the reason you expect.

This line evaluates to:

num2 = 1
num1 = (1 && num2) //wich turns out to be "true"

Since thie "&&" check turns out to be true, it assigns "true" (which is 1 in this case) to "num1". If it doesn't work, it's because of an 'lvalue' error.

I will assume you really want to make 'num1' and 'num2' both equal 1. In this case, there are a few ways to do it:

num1 = num2 = 1;

This assigns 1 to 'num2', and then the value of 'num2' to 'num1'. The end result is everything equals 1.

You could also do:

num1 = 1;
num2 = 1; //or num2 = num1;

The next problem in that block of code is your failure to use a 'break' statement at the end of your case.

The way a switch works is this: it matches the case, then it executes all code in the block, and stops once it encounters the end of the entire switch, or a 'break', whatever comes first. Thus:

Code:

switch( x )
{
    case 1:
        do_something( );
    case 2:
        do_something_else( );
    case 3:
        do_more( );
    break;
    case 4:
        do_more_more( );
    break;
}

If x is 1, then case 1 executes, then since no break is encountered, case 2 executes, then since no break is encountered, case 3 executes, then since a break is encountered, it stops.

You want to be sure you're using a 'break' before the next 'case' block, otherwise you'll get this sort of "drop through" effect.
}

//here is where i'd like to ask if its another customer (start over again without clearing array) or to just end the entire program. Ideas?

Wrap the process in a loop that exits if the valid is incorrect. Your switch can accomidate this. Consider the following example:

Code:

#include <stdio.h>

int main ( void )
{
    int choice = 0;

    while( choice != 'q' && choice != 'Q' )
    {

        puts("The menu text goes here."
        choice = getchar( ); //read the input
        getchar( ); //avoid the extra input read from the enter key

        switch( choice )
        {
            case '1':
                do_menu1( );
            break;
            case '2':
                do_menu2( );
            break;

            default:
                if( choice == 'Q' || choice == 'q' )
                    puts("Good bye.");
                else
                    puts("Invalid choice.");
        }
    }

    return 0;
}

This would give you a simple menu. You should be able to get something working from here.

Quzah.

Bit late but I think you should use int arrays for this.
I find int's easier to work with than characters and this is mainly a TRUE / FALSE question 'Is the seat full?', 'Is there room in non-smoking?'.

Watch your use of certain 'words'.
For example you use 'table' too much.
ie the function table() has a loop counter called table, an array called table.

Try TableAlloc() iTableIndex, and TableArray or that sort of thing. In the long run the extra typing will pay off. (after you have spent a few hours trying to find the place you used the wrong variable)

You have to give the arrays size.

So if you want 10 tables of 4 you will need to declare

char TableArray[10][4];

I would use a hash define and int array as easier to read in the long run.

Code:

#define    TABLE_SEATS      4
#define    NUM_TABLES       10

int    iTableArray[NUM_TABLES][TABLE_SEATS];

for(i=0;i<NUM_TABLES;i++)
{
    for(j=0;j<TABLE_SEATS;j++)
    {
        iTableArray[i][j]=0;
        //cTableArray[i][j]='O';
    }
}