error: expected ‘;’ before ‘generationString’ [closed] - c++

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I'm currently trying to work out some issues I am experiencing with this code, can't really figure out why I am getting these 2 errors.
I tried to see if something was not closed, but this not does seem to be the case, can be be cause of the distance between the ": "?
I'm just grasping for straws by now..
main.cpp:30:38: error: expected ‘;’ before ‘generationString’
cout << "Generation " << x << ": " generationString << endl;
main.cpp:54:40: error: expected ‘;’ before ‘generationString’
cout << "Generation " << x++ << ": " generationString << endl;
When trying to compile this code:
#include <iostream>
using namespace std;
string
initString ()
{
}
int
calculateScore (string guess, string target)
{
}
string
mutate (string mutationString)
{
}
int
main ()
{
string targetString = "METHINKS IT IS LIKE A WEASEL";
string generationString = initString ();
string currentString = generationString;
int score = calculateScore (currentString, targetString);
int x = 0;
cout << "Generation " << x << ": " generationString << endl;
do
{
for (int i = 0; i < 100; i++)
{
string newCopy = generationString;
newCopy = mutate (newCopy);
int copyScore = calculateScore (newCopy, targetString);
if (copyScore > score)
{
currentString = newCopy;
score = copyScore;
if (copyScore == targetString.length ())
{
break;
}
}
}
generationString = currentString;
}
while (score < targetString.length ());
cout << "Generation " << x++ << ": " generationString << endl;
return 0;
}

You're missing a <<.
cout << "Generation " << x << ": " generationString << endl;
Should be
cout << "Generation " << x << ": " << generationString << endl;
Likewise for
cout << "Generation " << x++ << ": " generationString << endl;
That should be
cout << "Generation " << x++ << ": " << generationString << endl;

You are probably missing a << in the line
cout << "Generation " << x << ": " generationString << endl;
Here you have
": " generationString
which should be
": " << generationString
C++ can concatenate literal strings, but it cannot concatenate literal string with anything else (like std::strings). So for instance this would work
cout << "Generation " << x << ": " "METHINKS IT IS LIKE A WEASEL" << endl;

Related

How to make while loop stop if it's <= 0 [closed]

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So I'm new to coding and I'm doing this for a class project. How do I make it where the while loop stops if it's <= to 0. If I put <= to 0 it doesn't do the loop at all and if I put it !=
it works, but it sometimes goes negative resulting in the loop never stopping. Is there something I'm missing? I have no idea why <= 0 wouldn't work
int main()
{
while (health != 0 && enemy_health != 0) {
std::cout << "Player " " Health: " << health << " Level: " << level << "\n";
std::cout << "Inventory " << "Gold: " << gold << " Keys: " << keys << " Health Potions: " << health_potions << "\n\n";
std::cout << "Fist: " << fist_damage << " damage " << " Torch: " << torch_damage << " damage \n" << " Status Effects:\n\n" <<" Burn: " << burn_damage << " damage\n\n";
std::cout << "Use: ";
std::cin >> input;
if (input == Fist) {
std::cout << "\nYou did " << fist_damage << " damage\n\n";
std::cout << "Monsters Health: " << enemy_health << "\n";
playerAttack = true;
}
else if (input == Torch) {
std::cout << "\nYou did " << torch_damage << " damage\n" << "You did " << burn_damage << " burn damage\n\n";
int total = enemy_health - (torch_damage + burn_damage);
enemy_health = total;
std::cout << "Monsters Health: " << enemy_health;
torch_durability--;
playerAttack = true;
isBurning = true;
}
while (playerAttack != true) {
std::cout << "\n\nPlease enter a valid answer\n\n";
std::cout << "Use: ";
std::cin >> input;
if (input == Fist) {
std::cout << "\nYou did " << fist_damage << " damage\n\n";
std::cout << "Monsters Health: " << enemy_health << "\n";
playerAttack = true;
}
else if (input == Torch) {
std::cout << "\nYou did " << torch_damage << " damage\n" << "You did " << burn_damage << " burn damage\n\n";
int total = enemy_health - (torch_damage + burn_damage);
enemy_health = total;
std::cout << "Monsters Health: " << enemy_health;
torch_durability--;
playerAttack = true;
isBurning = true;
}
}
if (playerAttack == true) {
std::cout << "\n\nThe enemy attacks\n\n";
}
if (dodge_chance == 5) {
std::cout << "\n\nYou dodged the enemies attack\n\n";
}
else if (dodge_chance != 5) {
std::cout << "The enemy landing a crushing blow\n\n";
playerHit = enemy1_damage;
int health_real = health - playerHit;
health = health_real;
std::cout << "The enemy does " << playerHit << " damage\n\n";
}
}
}
When asking questions or just for debugging, it is a good idea to isolate the part that is giving you trouble. Most of the code you have posted is irrelevant and makes it harder to read and test.
From what I understand, you have tried putting
while (health <= 0 && enemy_health <= 0)
instead of your current loop ?
If so, then it is simply a logic error. You are asking the code to loop while player health is negative or zero. Simply changing to
while (health > 0 && enemy_health > 0)
would work.

C++ int x++ and int ++x not working how I thought they would? [closed]

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I have a simple program but it's running weirdly. Basically the code runs fine but when the numbering at the beginning of the line comes into play, int x++ displays the same number as the first line then continues. Why does this happen?
Code:
#include "stdafx.h"
#include <iostream>
#include <windows.h>
#include <string>
#include "logo.h"
int main()
{
SetConsoleTitle("plains.exe");
displayLogo();
int number;
int addTotal = 0;
int numbersEntered = 0;
std::cout << " [1] enter your first number: ";
std::cin >> number;
while (number != -1) {
addTotal = addTotal + number;
numbersEntered++;
std::cout << " [" << numbersEntered << "]" << " enter your next number or type '-1' to add them: ";
std::cin >> number;
}
if (number == -1) {
std::cout << " " << std::endl;
std::cout << " --------------------------------" << std::endl;
std::cout << " " << std::endl;
std::cout << " the sum of your numbers is " << addTotal << "." << std::endl;
std::cout << " you entered a total of " << numbersEntered << " numbers." << std::endl;
std::cout << " " << std::endl;
std::cout << " the average of your numbers is " << addTotal / numbersEntered << "." << std::endl;
std::cout << " " << std::endl;
}
return 0;
}
You initialized numbersEntered to 0. The first time through the while loop, it does numbersEntered++, which sets it to 1. So the first prompt in the loop contains [1]. This is the same as what you printed before the loop with:
std::cout << " [1] enter your first number: ";
so you see [1] twice.
To prevent this duplication, add 1 to the variable when displaying the prompt:
std::cout << " [" << (numbersEntered++) << "]" << " enter your next number or type '-1' to add them: ";

c++ when using functions function call missing argument [closed]

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Closed 8 years ago.
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void Circle::getXYr() {
cout << "(x,y,R) = (" << x << "," << y << "," << r << ")" << endl;
}
double Circle::circArea() {
return (r * r * PI);
}
double Circle::circPeri() {
return (2 * r * PI);
}
void Circle::printCircle() {
cout << "Printing circle " << getXYr << endl;
cout << "Circle Area: " << circArea << endl;
cout << "Circle Perimeter: " << circPeri << endl;
}
I cant use the printCircle function: ERROR Error 1 error C3867: 'Circle::getXYr': function call missing argument list; use '&Circle::getXYr' to create a pointer to member
also the same for the next 2 functions.
It are functions, you have to call them as such. Note the brackets ()
cout << "Printing circle " << this->getXYr() << endl;
cout << "Circle Area: " << this->circArea() << endl;
cout << "Circle Perimeter: " << this->circPeri() << endl;
this-> is not explicitly needed.
Your second error is due this->getXYr() does not return a value. It returns void. There is no basic_ostream overload for it.
You either should put the logic of the getXYr() into the printCircle() function. Or call that function without calling cout on it:
cout << "Printing circle ";
this->getXYr();
cout << "Circle Area: " << this->circArea() << endl;
cout << "Circle Perimeter: " << this->circPeri() << endl;

Quotient program help me [closed]

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Hi i have problem with c++
#include <iostream>
#include <cstdlib>
using namespace std;
int main(int argc, char *argv[])
{
float a,b,wynik;
cout << "quotient" << endl
<< "..." << endl << endl
<< "quotient 2 numbers."
<< "\ndivisior does not equal 0"<< endl << endl;
cout << "a=";
cin >> a;
cout << "b=";
cin >> b;
if (b!=0)
cout << "\n" << a << " / " << b << " = " << a/b << "\n\n";
else
cout <<"\ndivisior does not equal 0!\n\n";
system("PAUSE");
return 0;
}
I must use for or while when someone try quotient number by 0.
If I understood correctly, you probably want to ask for input again if b is zero
You can have something like this :
do {
cout << "quotient" << endl
<< "..." << endl << endl
<< "quotient 2 numbers."
<< "\ndivisior does not equal 0"<< endl << endl;
cout << "a=";
cin >> a;
cout << "b=";
cin >> b;
if (b!=0)
cout << "\n" << a << " / " << b << " = " << a/b << "\n\n";
else
cout <<"\ndivisior does not equal 0!\n\n";
}while(b==0);
Your terms are wrong, see Wikipedia definition of "quotient".
#include <iostream>
int main(void)
{
char prompt[] =
"\n"
"Division, dividend / divisor = quotient:\n"
" Enter divisior: ";
int divisior;
int dividend;
while (true)
{
std::cout << prompt;
std::cin >> divisor;
if (divisor == 0)
{
std::cout << "\n* Divisor is zero, try again.\n";
continue;
}
std::cout << "\n Enter dividend: ";
std::cin >> dividend;
std::cout << "\nResult of "
<< dividend
<< " / "
<< divisor
<< " is, using integer division, "
<< dividend / divisor
<< "\n";
break;
}
return EXIT_SUCCESS;
}

I want to print out some values from 2-d array C++

I want to input data from txt file.
the file contains 2-d array [5][5]
how can i print out the any value i want?
i don't want to print out the whole 5*5 data
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main()
{
double distance[5][5] ;
string line;
ifstream ratefile;
ratefile.open("a.txt");
ofstream file;
if (ratefile.is_open())
{
while (! ratefile.eof() )
{
getline (ratefile,line);
ratefile.getline(distance, 25, '*');
cout << "\nDistance [0][0]" << ": " << distance[0][0];
cout << "\nDistance [0][1]" << ": " << distance[0][1];
cout << "\nDistance [0][2]" << ": " << distance[0][2];
cout << "\nDistance [0][3]" << ": " << distance[0][3];
cout << "\nDistance [1][0]" << ": " << distance[1][0];
cout << "\nDistance [1][1]" << ": " << distance[1][1];
cout << "\nDistance [1][2]" << ": " << distance[1][2];
cout << "\nDistance [1][3]" << ": " << distance[1][3];
cout << endl;
cin.get();
return 0;
}
If you only want to output one value and the user should be able to choose a value, you can do something like this:
int x, y;
cin >> x;
cin >> y;
cout << "\nDistance [" << x << "][" << y << "]" << ": " << distance[x][y];
But you should check if the user enter valid numbers (0 <= x < 4 and 0 <= y < 4)
There is part of the code missing, but you are printing values you want. Simply remove the lines you don't want to print.
Of course you can also use variables:
int x = 2,y = 2;
cout << endl << "Distance [" << x << "][" << y << "] : " << distance[x][y];