Simple Coke Machine problem

[falconsx23]

Hi,I want to create a coke machine that distributes cans with the cost of one token. All the cans in the coke machine coast the same. When a token is inserted, one can drops out. The coke machine should keep track of both cans and tokens count.

The problem I am having right now is finding the correct methods, especially one that allows one token to have one can come out. This is frustrating. Here is my program so far.

public class CokeMachine
{
    int number_tokens;
    int number_cans; 
    int token; 
    int can; 
 
    public CokeMachine()
    {
        number_cans = 50;
    }
 
 
        public void insertToken(int number_tokens)
        {
 
            token += number_tokens; // takes token, then adds number of tokens to token, then resign it back to token
 
        }
 
 
 
}
 

[HxRLxY]

If I understand you right, you want to decrease the coke count every time you increase the token count. So try this.

public void insertToken (int number_tokens)
{
     if (number_cans - number_tokens < 0) //not enough cokes left
     {
          System.out.println (/*some error message*/);  
     }
     else
     {
          tokens -= number_tokens;
          number_cans -= number_tokens;
     }
}
 

[chaarmann]

There should be a plus instead of a minus:
tokens += number_tokens;

[falconsx23]

Yes that is exactly what I want to do. Ill try it out

[falconsx23]

Ok I have compiled my program with the method you gave me. It displays no syntax errors, so everything seems to be working correctly. Here is the program with the methods you helped me with. From what I see from this prgram is that everytime a token is inserted, that token is being deducted from the number of tokens count. Then the number of cans is being deducted when the number of tokens is being deducted? Can you try to explain what is going on and see if I am understading the code correctly?

 
 
public class CokeMachine 
{ 
    int number_tokens; 
    int number_cans;  
    int tokens;  
    int can;  
 
    public CokeMachine() 
    { 
        number_cans = 50; 
    } 
 
 
        public void insertToken(int number_tokens) 
        { 
 
            tokens -= number_tokens; 
          number_cans -= number_tokens; // takes token, then subtracts one token from number of tokens, then resign it back to token 
 
        } 
 
 
 
} 
 
 

[chaarmann]

@falconsx23
It doesn't make sense to deduct the tokens. That's what the machine gets, so we need to add. The cans are what the machine gives away, so we need to subtract. Look what he wrote:
@HxRLxY
Did you notice the word "increase"? And look what I wrote in my previous post:.
@chaarmann
It seems it was just a mistyping in his program.

Anyway, you don't need the number_tokens variable (redundant information), you can always compute the number of tokens with "50 - number_cans". I assume that the guy who refills the machine also puts out all the tokens.

Remark:
To have a variable "number_tokens" makes only sense when the machine malfunctions and it takes the token without putting out the coke! Then you can check if the customer's complaint is true or not.

[falconsx23]

Sorry it took me so long to reply, but I completed the program. You are right it was not really making sense along with the mis spelling. This is what I did.

 
public class CokeMachine
{
 
    int number_cans; 
    int tokens; 
 
 
    public CokeMachine()
    {
        number_cans = 50; //already holds 50 cokes
 
    }
 
    public CokeMachine(int num)
    {
        number_cans = num; 
    }
 
        public void insertToken(int num)
        {
            tokens += 3;
            number_cans -= num; // takes token, then adds number of tokens to token, then resign it back to token
            System.out.println("The number of cans remaining are " + number_cans);
            System.out.println("The number of tokens are " + tokens);
            System.out.println("You get " + tokens + " cokes ");
 
        }
        public void insertcans(int num)
        {
          number_cans += num; 
        }
 
 
 
 
 
 
}
 

[JosAH]

Line #22 contains a typo or some testing leftover. If you insert 'num' tokens you get 'num' cans of coke if possible; you get less if the vending machine contains less than 'num' cans of coke.

kind regards,

Jos

[falconsx23]

o ok I see what you mean. Thanks alot