Array Of Pointers To Strings I Have An Array Of

Array Of Pointers To Strings I have an array of pointers to strings (char *name[maxnum]). I add elements to the array and output each element right after to check their content and it is okay. char[counter] = value; cout << char[counter] << endl; However, at a later point in the code I output all the elements, and they are all equal to element the last element (maxnum). :-( for (int i=0;i<=maxnum;i++) { cout << char[i] << endl; } I do a similar process with an array of doubles (double [maxnum]) and the process above works fine. Note that I do not want to use strings. Can you help figure out what is wrong when I use the array of pointers to store strings? // Homework1.cpp : Exercise 2.56: Program to compute weekly payroll // for a company // Written by: Michelle M. Irizarry-Ortiz // #include #include using namespace std; // Function declaration void eatline(); // Global variables char mainMenuSelection = ' '; char employeeName[40]; char employeeType; int main() { // Constant declarations const int maxEmployees = 100; const double hrThreshold = 40.0, wklyCommSalary = 250., overTimeRatio=1.5, wklySalesPerc=5.7; // Variable declarations int numberItems, val_employee_counter=0; double wklyPay = -1., fixedWklySalary, hourlyWage, hoursWorked, grossWklySales, ratePerItem, validwklyPay[maxEmployees]; char *validEmployeeName[maxEmployees];

// While user does not want to quit program while (mainMenuSelection != 'Q' && mainMenuSelection !='q') { // Display main menu cout << "\n"; cout << "**************************************\n"; cout << "***** WELCOME TO PAYROLL PROGRAM *****\n"; cout << "* *\n"; cout << "* E - Enter employee information *\n"; cout << "* P - Print report *\n"; cout << "* C - Clear database *\n"; cout << "* Q - Quit program *\n"; cout << "* (To quit a module, enter '!' *\n"; cout << "* at any time) *\n"; cout << "* *\n"; cout << "**************************************\n\n"; cout << " Enter letter from above menu: "; // Get menu selection from user if (cin.peek() == '!') {eatline(); break;} cin >> mainMenuSelection; eatline(); // To empty input stream in case // more than one character is entered // If user wants to enter employee info if (mainMenuSelection == 'E' || mainMenuSelection == 'e') { while (wklyPay < 0) { // Display employee info form cout << "\n"; cout << "**************************************\n"; cout << "***** EMPLOYEE INFO FORM *****\n"; cout << "**************************************\n"; cout << " Enter employee name: " << endl; //Get employee name if (cin.peek() == '!') {eatline(); break;} cin.get(employeeName,40,'\n'); // To be able to enter whitespace eatline(); cout << "\n Employee types:\n"; cout << " 1 - Manager\n"; cout << " 2 - Hourly worker\n"; cout << " 3 - Commission worker \n"; cout << " 4 - Piece worker\n"; cout << " Enter employee type (1-4): "; // Get employee type if (cin.peek() == '!') {eatline(); break;} cin >> employeeType; //Note: Need to flush input stream so ok if more than one character is entered eatline(); // To empty input stream in case // more than one character is entered cout << "\n"; // Enter additional employee information // depending on type

// Change output precision for dealing with currency cout << fixed << setprecision(2); switch (employeeType) { case '1': // manager cout << " Enter fixed weekly salary: "; if (cin.peek() == '!') {eatline(); break;} cin >> fixedWklySalary; wklyPay = fixedWklySalary; break; case '2': // hourly worker cout << " Enter hourly wage: "; if (cin.peek() == '!') {eatline(); break;} cin >> hourlyWage; cout << " Enter hours worked: "; if (cin.peek() == '!') {eatline(); break;} cin >> hoursWorked; if (hoursWorked <= hrThreshold) { wklyPay = hourlyWage * hoursWorked; } else { wklyPay = hourlyWage * (hrThreshold + 1.5 * (hoursWorked-hrThreshold)); } break; case '3': // commision worker cout << " Enter gross weekly sales: "; if (cin.peek() == '!') {eatline(); break;} cin >> grossWklySales; wklyPay = wklyCommSalary + grossWklySales * wklySalesPerc / 100; break; case '4': // piece worker cout << " Enter items produced: "; if (cin.peek() == '!') {eatline(); break;} cin >> numberItems; cout << " Enter rate per item: "; if (cin.peek() == '!') {eatline(); break;} cin >> ratePerItem; wklyPay = numberItems * ratePerItem; break; default: // default cout << "Incorrect employee type entered.\n"; cout << "Try again!\n"; break; // Need to go back to enter employee info if something is wrong } // end switch // Store valid data into arrays for summary report if (wklyPay >= 0.) {

cout << "\nPay for employee " << employeeName << ": $" << wklyPay << endl; validwklyPay[val_employee_counter] = wklyPay; validEmployeeName[val_employee_counter] = new char[40]; validEmployeeName[val_employee_counter] = employeeName; cout << "here" << val_employee_counter << validEmployeeName[val_employee_counter] << endl; for (int i=0;i<=(val_employee_counter);i++) { cout << "here2!!! " << validwklyPay[i] << " " << &validEmployeeName[i] << endl; } val_employee_counter++; } // end if } // end while wklyPay = -1.; // Restore weekly pay to -1 cout << validEmployeeName[0] << endl; } // end if else if (mainMenuSelection == 'P' || mainMenuSelection == 'p') { if (val_employee_counter >= 1) { //Issue: If second employeename is too long, first will be sub by it cout << endl << endl; cout << setw(40) << left << " Employee Name" << setw(15) << right << " Pay " << endl; cout << setw(40) << left << " *************" << setw(15) << right << "*******" << endl; for (int i=0; i<=(val_employee_counter-1); i++) { cout << i+1 << ". " << setw(40) << left << validEmployeeName[i] << "$" << setw(14) << right << validwklyPay[i] << endl; } cout << endl << endl; } // end if else { cout << "\nNo employee information has been entered!\n"; } // end else } // end else if else if (mainMenuSelection == 'C' || mainMenuSelection == 'c') { val_employee_counter = 0; } // end else if } // end while return 0; } // Function to eat remainder of line void eatline() { while(cin.get() != '\n') continue; }

The statements/blocks in question are: char *validEmployeeName[maxEmployees]; validEmployeeName[val_employee_counter] = employeeName; for (int i=0; i<=(val_employee_counter-1); i++) { cout << i+1 << ". " << setw(40) << left << validEmployeeName[i] << "$" << setw(14) << right << validwklyPay[i] << endl; } ou are using arrays of char. You want to use strcpy() to copy the names: Your program does this: CPP / C++ / C Code: validEmployeeName[val_employee_counter] = employeeName; This makes the pointer point to the employeName array, whose content changes for each entry, and finally it contains the last employee name that was entered. In other words, all of your validEmployeeName[] pointers end up pointing to the employeeName array, therefore the output will show them to be the same. To get the name into the pointer array element that you just obtained from new, use strcpy. CPP / C++ / C Code: // at the top of the file: use this header for strcpy() #include // // Instead of your statement use this: strcpy(validEmployeeName[val_employee_counter], employeeName); //

(Also setting validEmployeeName[...] equal to something other than the value given by new means that the memory can never be freed. This is a Bad Thing. It is the programmer's responsibility to make sure that for every memory block obtained by new it is returned to the operating system by a delete before exiting. This is important!) Hi! Thanks! This worked. Now it makes sense! My only question is: how do I use delete to free up the memory for every pointer in the array? Within the 'C' option, I tried a single: delete [] validEmployeeName; but it did not work. :-( Do I need a loop? Ok! Got it: for (int ctr=0; ctr<=(val_employee_counter - 1); ctr++){ delete [] validEmployeeName[ctr]; } Finally getting the hang of it