Problems compiling program (expected primary-expression, unqualified-id)

[tnwagn]

I have been working on a program and have been unable to resolve these compile issues.

g++ main.cpp -o project5.exe
main.cpp: In function 'int deal()':
main.cpp:20: error: expected primary-expression before '.' token
main.cpp:21: error: expected unqualified-id before '.' token


Inside program main is this (outside of main() )

int deal() {
 
  int dealcard = cards.front();
  cards.erase(cards.begin());
  return dealcard;
} //End function deal

Where line 3 in the code posted relates to line 20 in the error part above.

I know this is only a small part of the program, but perhaps someone could tell me my problem without me having to post up the entire code.

Thanks a bunch!

[gpraghuram]

I have been working on a program and have been unable to resolve these compile issues.

g++ main.cpp -o project5.exe
main.cpp: In function 'int deal()':
main.cpp:20: error: expected primary-expression before '.' token
main.cpp:21: error: expected unqualified-id before '.' token


Inside program main is this (outside of main() )

int deal() {
 
  int dealcard = cards.front();
  cards.erase(cards.begin());
  return dealcard;
} //End function deal

Where line 3 in the code posted relates to line 20 in the error part above.

I know this is only a small part of the program, but perhaps someone could tell me my problem without me having to post up the entire code.

Thanks a bunch!

Can you tell me how u have declared the variable cards

Raghuram

[tnwagn]

At the top of the program after my #include statements I have

class cards;

cards is basically a vector created by the shuffle function

const int SIZE = 52;
  int a1 [SIZE]= {1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8\
,8,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10};
  std::vector < int > cards(a1, a1 + SIZE);

[gpraghuram]

cards is a class and the front() method you are calling belongs to the vector.
Or do u have a method front() in the call cards?

Raghu

[tnwagn]

What I am doing with theses is creating a vector of 52 cards and then shuffling them in the first function "shuffle()" in this function I create the vector "cards". In the second function "deal" I take the first element of the vector "cards" with the command .front() (which are available for all swqunece containers). I then erase the first element of the vector with .erase (available in first class containers).

When attempting to compile I get the errors mentioned above.

Here is that includes those parts

class cards;
 
void shuffle() {
 
  const int SIZE = 52;
  int a1 [SIZE]= {1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8\
,8,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10};
  std::vector < int > cards(a1, a1 + SIZE);
  std::ostream_iterator< int > coutput( cout, " ");
 
  random_shuffle(cards.begin(), cards.end());
} //End function shuffle
 
int deal() {
 
  int dealcard = cards.front();
  cards.erase(cards.begin());
  return dealcard;
} //End function deal

Thanks for the help.

[weaknessforcats]

class cards;

You are using a forward reference.

Question: How the the compiler know there is a front() method.

Answer: It doesn't.

There's your error.

A forward reference is enough for the compiler to allow a pointer to your class but if you do more than that, you need to include the class declaration.

[tnwagn]

Thanks for the help everyone. I, with the help of some friends, been able to compile the program with no errors. However, I am now getting Segmentation Fault when I try and run the program. This is, from what I've read, when the program calls areas of memory it doesn't have acess to. So here is the entire thing. Let me know if you can find any reason why it is returning a segmentation fault.

#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;
 
class cards;
 
  const int SIZE = 52;
  int a1 [SIZE]={1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8,8,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10};
  std::vector < int > cards(a1, a1 + SIZE);
 
 
 
void shuffle() {
 
  random_shuffle(cards.begin(), cards.end()); //Shuffle cards
} //End function shuffle
 
int deal() {
 
  int dealcard = cards.front(); //Deal first card from deck
  cards.erase(cards.begin()); //Remove first card from deck
  return dealcard; //Output total of card delt
} //End function deal
 
int player() {
 
  int firstcard = deal();                //Get first card for blackjack
  int secondcard = deal();               //Get second card for blackjack
  int sumcards = firstcard + secondcard; //Then add the total of the two cards to see
  while(sumcards < 17) {                 //If score is less than 17
    int nextcard = deal();               //If it is get another card
    int sumcards = sumcards + nextcard;  //And see if the sum is still less than 17
  }                                      //If it is still less than 17 loop and get another card
  return sumcards;                       //If the score is 17 or more, output the total score
} //End function player
 
 
int main(){ //Start main function
 
  int counter = 0;  //counter for number of loops
  int i, results, total;   //declare variables
 
  vector<int>scores; //Create vector to hold scores of deals
  ostream_iterator<int>output(cout, " ");
 
  while (counter<100000){  //Start loop, conitune 100000 times
    counter = counter + 1; //Increase counter by 1 each loop
 
    shuffle(); //Shuffle the cards
    total = player(); //Take cards and find final value of all cards
 
    scores.push_back(total); //Add scores to vector
  }
 
  while(i=0, i<31, i++){
      results = count(scores.begin(), scores.end(), i);
      cout << results << ": Number of times scored " << i << endl;
  }
 
  return 0;
}
 

Thanks for the help once again.

[weaknessforcats]

Your deal() function is erasing elements from the vector. That's OK if there are elements to erase. Otherwise: KA-BOOM.

I don't see any provision for checking this.

Also, your class cards is pointless. Did you know that the vector has the same name?

Please read this article http://www.thescripts.com/forum/thread737451.html.

[tnwagn]

Please read this article http://www.thescripts.com/forum/thread737451.html.

After reading this it sounds like you would want me (and it would be better for me) to, instead of having the vector "cards" be global, put it inside of a function. This is the way I originally had it set up. However, my other functions inside of the program (mostly deal() ) where unable to acess the vector when it was inside of the shuffle() function. So would you say to put the vector "cards" definition inside of it's own function and then have all the others call that function instead of the vector?

Your deal() function is erasing elements from the vector. That's OK if there are elements to erase. Otherwise: KA-BOOM.

I don't see any provision for checking this.

This program is supposed to run through the shuffle,deal, get a hand routine 100,000 times. What is happening then I guess is that the vector of "cards" is never being reinitilized with 52 cards so after the first few runs it runs out of cards and, as you say, goes ka-boom. I imagine that it would work if it only had to loop around 20 times.

Also, your class cards is pointless. Did you know that the vector has the same name?

Yes, I knew that cards was the same for the class name as well as the vector name. However, I do not completely understand the entire "class" thing. From what I've gathered so far is that you have to define the vector as some sort of class. I guess that is horribly wrong. I will take the line involving class out and see if that works.

[tnwagn]

I still have the Segmentation error when I try and run the program. I have no idea exactly why it is coming up but I do know of at least one problem.

The "deck" is created at the beginning globally. This is so that every other function can acess it. However, I've been told that's wrong.

But I don't understand how to put a vector into a function and still have other functions be able to call that vector and perform operations on it.

I really to find a solution to this. Can someone help me out?