It's the first time I'm trying something with String Arrays in C++ and yep... I'm stuck.
I'm trying a small programm which will let the user enter max. 10 random Names. If the user enters '.' or has entered 10 nNames the input dialog will end. After he has done this all names will be printed out.
I tried it with a vector, but I guess I be doing something completely wrong...
#include <iostream>
#include <vector>
using namespace std;
int main()
{
char name;
int i, counter;
vector<string> namen_vec;
cout << endl << "Eingabedialog von maximal 10 Namen. " << endl;
cout << "Eingabe kann fruehzeitig mit '.' beendet werden. " << endl;
cout << "--------------------------------------------------" << endl << endl;
counter = 0;
do
{
cout << "Eingabe Name: ";
cin >> name;
namen_vec.push_back(name);
counter++;
} while (name != '.' && counter <= 9);
for (int i = 0; i < namen_vec.size(); i++)
{
cout << namen_vec[i] << endl;
}
return 0;
}
Maybe someone has one or two advices?
First of all, you have declared the variable name as char but your container vector namen_vec accepts a string. Still, the program won't be compiled successfully because the following line
while (name != '.' && counter <= 9);
as name would be a string then you have to change this as
while (name != "." && counter <= 9);
Related
This is a program that grade user inputs for the questions of Driver's License Exam.
I'm having trouble of validating the user input.
I'd like to accept the [ENTER] key as an invalid input and proceed to my validation rather than just go to an empty line and cannot process to the next question. Purpose is to send out error message and that no input is given and [ENTER] key is not valid input and only accept one more chance to enter valid input which are a/A, b/B, c/C, or d/D. So that is why I'm using if statement here instead of loop.
I tried if (testTakerAnswers[ans] == (or =) '\n') {} but still doesn't solve the problem of newline.
I include curses.h in here hope to use getch() statement from the other post but somehow I can't manage to work in my code with an array instead of regular input.
I'm looking for other methods as well rather than getch()
So should I adjust my bool function, or directly validate input in main() function.
#include <iostream>
#include <iomanip>
#include <string>
#include <cctype>
#include <curses.h>
using namespace std;
const unsigned SIZE = 20; // Number of qns in the test
char testTakerAnswers[SIZE]; //Array to hold test taker's answers
bool validateInput(char);
class TestGrader
{
private:
char answers[SIZE]; // Holds the correct answers // Answer is array
int getNumWrong (char[]);
void missedQuestions (char[]);
public:
void setKey(string); // Initialize object with standard keys
void grade(char[]); // Grades the answers from tester
};
void TestGrader::setKey(string key){
if (key.length()!=SIZE){
cout << "Error in key data.\n";
return;
}
for (unsigned pos = 0; pos < SIZE ; pos ++)
answers [pos] = key [pos];
}
void TestGrader::grade(char test[])
{
int numWrong = getNumWrong(test);
if (numWrong <= 5)
cout << "Congratulations. You passed the exam.\n";
else
cout << "You did not pass the exam. \n";
cout << "You got " << (SIZE-numWrong) << " questions correct. \n";
if (numWrong > 0){
cout << "You missed the following " << numWrong << " questions: \n";
missedQuestions(test);
}
}
int TestGrader::getNumWrong(char test[])
{
int counter = 0;
for (int i = 0; i < SIZE; i++){
if (answers[i] != toupper(testTakerAnswers[i])){
counter++;
}
}
return counter;
}
void TestGrader::missedQuestions(char test[])
{
// cout << testTakerAnswers[i]; This is to print taker's answers
int counter = 0;
for (int i = 0; i < SIZE; i++){
if (answers[i] != toupper(testTakerAnswers[i])){
cout << "\n" << i + 1 << ". Correct answers: " << answers[i];
counter++;
}
}
}
bool validateInput(char ans){ // Only A, B, C, D valid input
if (toupper(ans)!='A' && toupper(ans)!= 'B' && toupper(ans)!='C' && toupper(ans)!= 'D'){
cout << "\n********************WARNING*******************\n";
cout << "Invalid input! Enter only a/A, b/B, c/C, or d/D\n";
return false;
}
if (testTakerAnswers[ans] == '\n'){
return false;
}
return true;
}
int main()
{
const int NUM_QUESTIONS = 20;
string name; //Test taker's name
char doAnother; //Control variable for main processing loop
TestGrader DMVexam; //Create a TestGrader object
DMVexam.setKey("BDAACABACDBCDADCCBDA");
do {
cout << "Applicant Name: ";
getline(cin,name);
cout << "Enter answer for " << name << ".\n";
cout << "Use only letters a/A, b/B, c/C, and d/D. \n\n";
for (int i = 0; i < NUM_QUESTIONS; i++){
// Input and validate it
do{
cout << "Q" << i+1 << ": ";
cin >> testTakerAnswers[i];
if (!validateInput(testTakerAnswers[i])){
cout << "You get one more chance to correct.\nOtherwise, it count as wrong answer.";
cout << "\n*********************************************";
cout << "\nRe-enter: ";
cin >> testTakerAnswers[i];
cout << '\n';
break;
}
}while(!validateInput(testTakerAnswers[i]));
}
//Call class function to grade the exam
cout << "Results for " << name << '\n';
DMVexam.grade(testTakerAnswers);
cout << "\nGrade another exam (Y/N)? ";
cin >> doAnother;
while (doAnother != 'Y' && doAnother != 'N' && doAnother != 'y' && doAnother != 'n'){
cout << doAnother << " is not a valid option. Try Again y/Y or n/N" << endl;
cin >> doAnother;}
cout << endl;
cin.ignore();
}while(doAnother != 'N' && doAnother != 'n');
return 0;
}
Your issue is cin >> testTakerAnswers[i]; cin is whitespace delimited, that means that any whitespace (including '\n') will be discarded. So testTakerAnswers[i] can never be '\n'.
I'm not sure exactly what you want to do, but possibly try
getline(cin,input_string);
then
input_string == "A" | input_string == "B" | ...
So if only the enter key is pressed, input_string will become "".
Currently I am working on a hangman game, I had previously coded it to only work for a 5 letter word, but now would like to make it handle any length of word, how could I change this code to make it work how I want it to?
#include "stdafx.h"
#include <iostream>
#include <string>
#include <stdlib.h>
#include <cstdlib>
using namespace std;
int main()
{
string word;
int tries;
string guess;
string wordguess;
string output;
cout << "Enter a word for player two to guess: ";
cin >> word;
system("CLS");
cout.flush();
cout << "Guess the word!" << endl;
for (int i = 0; i < word.length(); i++)
{
cout << "_ ";
}
cout << "Enter a letter: ";
cin >> guess;
for (int tries = 5; tries > 0; tries--)
{
if (guess[0] == word[0]) {
output[0] = word[0];
cout << "You guessed the first letter! Good job!" << endl;
}
if (guess[0] == word[1]) {
output[2] = word[1];
cout << "You guessed the second letter! Good job!" << endl;
}
if (guess[0] == word[2]) {
output[4] = word[2];
cout << "You guessed the third letter! Good job!" << endl;
}
if (guess[0] == word[3]) {
output[6] = word[3];
cout << "You guessed the fourth letter! Good job!" << endl;
}
if (guess[0] == word[4]) {
output[8] = word[4];
cout << "You guessed the fifth letter! Good job!" << endl;
}
cout << output << endl;
cout << "You have " << tries << " tries left. Take a guess at the word: " << endl;
cin >> wordguess;
if (wordguess == word)
{
cout << "Congratulations, you guessed the word correctly!" << endl;
break;
}
}
system("pause");
return 0;
}
As you can tell I was checking each position from 0 to 4 (first through fifth letter). I know there are plenty of ways that I could have coded this better but as you can guess, I am new to coding and this is the way I thought of it. Please note this is still a work in progress so it is not fully complete. Any help would be great!
When designing an algorithm, think of how you would do this by hand, without a computer. Then let the code do the same.
If you were checking your friend's guess against a word written on sand, you would probably go about it like this:
go through the written pattern character by character, pronouncing your word in memory
for each letter, check if it is equal to the guess
if it is
replace the placeholder with it
memorize that your friend guessed right.
Also note if there are any placeholders left
if there aren't, your friend wins
finally, if your friend didn't guess right, score them a penalty point and check if they lose
Now, all that leaves is to put this down in C++. The language provides all sorts of entities - let's check which ones fit ours needs the best:
the word and the current pattern - strings of a fixed size
bits to memorize:
whether the current guess is right - bool
placeholders left - int
penalty points (or, equivalently, attempts left) - int
parts of the algorithm:
looping over a string - for loop of one of a few kinds
we need to replace the character in the pattern at the same index as the guessed letter in the word. So, we need to have the index when looping. Thus the flavor with the index variable, for(std::string::size_type i = 0; i < str.size(); ++i) probably fits the best.
// Example program
#include <iostream>
#include <string>
using namespace std;
class my_game
{
private:
string congrats_array[15] = {"first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "nineth", "tenth", "eleventh", "twelfth", "thirteenth", "fourteenth", "fifteenth"};
string word_to_guess;
int tries_left;
int word_length;
int letters_guessed_count;
string guessed_letters;
void check_letter(char letter);
void print_current_word_state();
public:
my_game();
void begin_the_game();
void play_the_game();
};
my_game::my_game()
{
}
void my_game::begin_the_game()
{
cout << "Enter a word for player to guess: " << endl;
cin >> word_to_guess;
system("CLS");
cout.flush();
cout << "Enter the tries amount!\n" << endl;
cin >> tries_left;
word_length = word_to_guess.size();
guessed_letters = "_";
letters_guessed_count = 0;
for(int i = 0; i < word_length - 1; i++){
guessed_letters += "_";
}
}
void my_game::play_the_game()
{
cout << "Guess the word!" << endl;
char letter;
for(int i = 0; i < tries_left; i++)
{
cout << guessed_letters << endl;
cout << "Enter a letter: " << endl;
cin >> letter;
check_letter(letter);
if(letters_guessed_count == word_length){
cout << "Congrats! You won!" << endl;
return;
}
}
cout << "You lose" << endl;
}
void my_game::check_letter(char letter)
{
for(int i = 0; i < word_length; i++)
{
if(word_to_guess[i] == letter && guessed_letters[i] != letter)
{
guessed_letters[i] = letter;
letters_guessed_count++;
cout << "You guessed the" << congrats_array[i] <<"letter! Good job!" << endl;
}
}
}
int main()
{
my_game game;
game.begin_the_game();
game.play_the_game();
}
So, in short what you need to do this with words of any arbitrary length is to use string's .substr() function and the stringstream library's .str() and << and >> operators. This version of your code uses a function that inserts a correctly guessed character at the appropriate indexed location. This will gradually replace the "_________" with letters at the correct places. This is much easier to do in Java, but stringstream is a good library I would highly recommend getting familiar with it. I'll leave the problem of how to handle multiple instances of a guessed character up to you (ie 'i' in "bibliography")
#include <string>
using std::string;
#include <sstream>
using std::stringstream;
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
string newString(string, int, string);
int main()
{
string word;
string guess;
int tries;
string output;
string input;
cout << "Enter word for player 2 to guess: ";
cin >> word;
stringstream ss;
//---------- fills the stream with "_"s matching the length of word
for(int i = 0; i < word.length(); i++)
ss << "_";
//----------- assigns the initial value of "___..." to output
ss >> output;
//----------- sets up the loop
tries = 5;
bool found = false;
for(int i = 0; i < 5; i++)
{
cout << "\nTry " << i << " of 5: Enter a letter or guess the word: ";
cin >> input;
if(input == word)
{
cout << "Congratulations, you guessed the word correctly!" << endl;
break;
}
//------------------ else, proceed with replacing letters
if(word.find(input) != std::string::npos)
{
size_t position = word.find(input); // finds index of first instance of the guessed letter
cout << "You guessed the " << position+1 << " letter! Good job!" << endl; // since strings start at index 0, position+1
//------- replaces appropriate "_" with the guessed letter
output = newString(input, position, output);
cout << "\n" << output;
// Around here you'll want to set up a way to deal with multiple instances
// of the same letter
}
else
cout << "Incorrect guess" << endl;
}
return 0;
}
//---------------------------------------------------
string newString(string guess, int index, string word)
{
string NewString;
stringstream temp;
//---------- hack up the string into sections before and after the index
string before = word.substr(0, index);
string after = word.substr(index+1, word.length() - index+1);
//---------------- populates the new stringstream and assigns it to the result
temp << before << guess << after;
NewString = temp.str();
return NewString;
}
I have to make a simple letter guessing game. So far I've finished almost everything but I'm not sure about what to do when it comes to one task.
So before the game begins it asks the user to input two things:
Enter the amount of different characters: (if 4 is entered for example, the letters chosen would be from A to the 4th letter, A-D only)
and
Enter the pattern length:
The pattern length input is working fine, but I'm having a tough time figuring out how to modify the generate code function to add the amount of different characters.
Any tips?
#include <iostream>
#include <random>
#include <string>
using namespace std;
size_t len;
string str;
void generate_code()
{
str.string::reserve(len);
random_device rd;
mt19937 gen{rd()};
uniform_int_distribution<char> dis{'A', 'Z'};
for (size_t i = 0; i < len; i++)
{
str += dis(gen);
}
}
void guess_checker()
{
string guess{};
size_t trial_count = 0, match_count = 0;
do
{
cout << "Enter your guess: " << endl;
cin >> guess;
if (guess.size() != len)
{
cout << "error: invalid guess" << endl;
}
else
{
match_count = 0;
for (size_t i = 0; i < len; i++)
{
if (guess[i] == str[i])
++match_count;
}
cout << "You guessed " << match_count << " character"
<< (match_count == 1 ? "" : "s") << " correctly." << endl;
}
++trial_count;
}
while (match_count != len);
cout << "You guessed the pattern in " << trial_count << " guess"
<< (trial_count == 1 ? "" : "es") << "." << endl;
}
int main()
{
int amount;
cout << "Enter the amount of different characters: ";
cin >> amount;
cout << "Enter the pattern length: ";
cin >> len;
generate_code();
guess_checker();
return 0;
}
Simply change your generator line to:
uniform_int_distribution<char> dis{'A', 'A' + amount - 1};
I would also recommend adding some validation beforehand, such as:
if (amount < 1 || amount > 26) {
cout << "Bad amount" << endl;
// exit or something
}
For my assignment, I have to call a function that takes the user input and spits out the number of non-whitespace characters. Inside the program, I have this code:
int GetNumOfNonWSCharacters(const string givenText) {
int counter;
for (int i = 0; i < givenText.length(); i++) {
if (givenText.at(i) != ' ') {
counter++;
}
}
return counter;
}
When I return the counter integer, this is how I output it with the string sampleText being the input:
if (menuInput == 'c' || menuInput == 'C') {
cout << "Number of whitespaces: " << GetNumOfNonWSCharacters(sampleText) << endl;
}
It returns an answer like 1231341235 or something along those lines. Now, when I type this code into a different file, pretty sure it's identical, I get the correct result every time:
int NumNonWhitespaces(const string userInput) {
int counter;
for (int i = 0; i < userInput.length(); i++) {
if (userInput.at(i) != ' ') {
counter++;
}
}
return counter;
}
int main() {
string userString;
cout << "Enter some text" << endl;
getline(cin, userString);
cout << "You entered: " << userString << endl;
cout << NumNonWhitespaces(userString);
return 0;
}
Does anyone have a solution to the problem ?
There is even more simple way to count the number of non white spaces by using the STL count algorithm:
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
string userString;
cout << "Enter some text" << endl;
getline(cin, userString);
cout << "You entered: " << userString << endl;
//count the number of white spaces
int numberOfWhiteSpace = count(userString.begin(), userString.end(), ' ');
//substruct that number from the total length of your string
cout << "number of non-whitespace: " << userString.length() - numberOfWhiteSpace;
return 0;
}
But in your solution you have to initialize the variable counter to 0
If you use counter without initializing it first, you'll get whatever junk memory existed at its memory address before your program started using it (C++ does not automatically zero-out the memory when you declare a variable). The fact it works when you copy it into a new file is purely coincidental.
The fix is simply to initialize counter to 0 before using it:
int counter = 0;
In some programming languages if a variable is allocated but not assigned, it is said to have a "garbage value" , that is, some information that was being held any random piece of the computer's memory. So initialize the counter variable to 0
You have to initialise the counter variable otherwise it will contain any old value.
int counter=0;
Here is the deal guys:
I'm making a stat generator. The program has a menu(not fully developed in this program, but I have previous code that will work)It asks for a name and then stores it to Character1.
Then it prompts that it is generating your scores.The function GenerateScore() takes 3 random numbers with the range 1-6 each, adds them together and returns the sum.
I want this to loop 6 times and store total into the array Stats[6].
Then I am sending the Character1 and the array to the txt file called charactersave.txt.
It saves whatever name I input each time but I get this when I open the txt file. I get this
anthony-858993460-858993460-858993460-858993460-858993460-858993460-858993460-117763858413957408144036511139574241439271911568132815670376-1177638760
Any help on this would be greatly appreciated,
#include <iostream>
#include <cstring>
#include <array>
#include <string>
#include <fstream>
using namespace std;
int GenerateScore();
int main()
{
int Stats[6];
char Selection;
string Character1;
int i;
cout << "Hello, welcome to my character generator. Please select an option" << endl;// Menu Options
cout << "A: Create Character Name and generate stats" << endl;
cout << "B: Display Name and Stats" << endl;
cout << "C: Quit" << endl;
cin >> Selection; // Menu Selection
cout << endl;
do
{
if ( (Selection == 'a') || (Selection == 'A') )// if user selects a, this happens
{
cout << "Welcome, Before you can start your adventures you must name your character." << endl;
cout << "Please enter your a name." << endl;// prompts user to enter a name for their Caracter
cin >> Character1;
cout << "Thank you now lets generate your stats." << endl;
for (i=0; i<6;i++)// I Want this to run the function GenerateScore() 6 times and input each result into the next element of Stats[6]
{
GenerateScore()>> Stats[i];
}
ofstream savecharinfo("charactersave.txt");// saves the Name and the filled array Stats[6] to the charactersave.txt file
if(savecharinfo.is_open())
{
savecharinfo << Character1;
for(int i = 0; Stats[i]; i++)
{
savecharinfo << Stats[i]; //writing numbers of values2 in the file
}
}
else cout << "File could not be opened." << endl;
break;// this is unfinished after this point
}
}
while ( (Selection != 'c') || (Selection == 'C') ); // ends the program if c or C is entered.
system("PAUSE");
return 0;
}
int GenerateScore()
{
int roll1 = rand()%6+2;
int roll2 = rand()%6+2;
int roll3 = rand()%6+2;
int sum;
sum=roll1+roll2+roll3;
return sum;
}
>> can only be used for std::ostream to achieve streaming behavior.
Change
GenerateScore()>> Stats[i];
to
Stats[i] = GenerateScore();