Identifier response is undefined and expected a ; [closed] - c++

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In my c++ course, I have been asked to generate a random number between 1 and 12 and add it to a sum. The program will ask if the user wants to add another number with the input y or n, and if the input is y it will add another number. When the sum reaches 50, the program will automatically end.
However, on lines 14 and 27, I get the error:
Expected a ;
And on line 16 I get the error:
identifier response is undefined
#include <iostream>
#include <iomanip>
using namespace std;
void rng(){
int rng = ((rand() % 12) + 1);
cout << rng;
}
int main()
{
int sum = 0
char response;
cout << "Would you like to add a number? y or n";
cin << response;
while (response = 'y') {
cout << "Would you like to add a number? y or n";
cin << response;
cout << "Okay then, the current sum is" << +" " << +sum << +rng;
if (response = 'n')
cout << "Okay thanks, have a good one";
if (sum > 50)
cout << "Alright the sum has reached 50 that seems like enough"
break
};
}

Answer 1

There are a number of mistakes in your code - some related to syntax errors, and some related to logic issues.
Regarding the syntax errors:
int sum = 0
needs to be
int sum = 0;
A semicolon ends a statement.
cin << response;
needs to be
cin >> response;
operator<< is used for output, whereas operator>> is used for input.
cout << "Okay then, the current sum is" << +" " << +sum << +rng;
needs to be
cout << "Okay then, the current sum is " << sum;
Using + on sum is redundant, but using + on rng is just plain wrong, since rng is a function, not a variable.
cout << "Alright the sum has reached 50 that seems like enough"
needs to be
cout << "Alright the sum has reached 50 that seems like enough";
Again, a semicolon ends a statement.
break
needs to be
break;
Again, a semicolon ends a statement.
Regarding the logic issues:
there is no need for #include <iomanip>, as you are not utilizing any stream manipulators.
you are missing #include <cstdlib> for rand().
rng() is a function, but the statement cout << ... << +sum << +rng; is trying to print it out as if it were a variable instead. The project requirement is to add the random number to the running sum, so rng() should return the number it generates, and then main() can add that number to sum before printing it out.
you are not calling srand() to initialize the random number generator before calling rand() the 1st time.
while (response = 'y') needs to be while (response == 'y'). operator= is for assignment, operator== is for comparison. That said, you should use a do..while loop instead, as there is no point in prompting the user twice on the 1st loop iteration.
if (response = 'n') needs to be if (response == 'n'). Again, assignment vs comparison. Also, you are also not break'ing the loop if the user enters 'n'.
if (sum > 50) is missing {} braces, so the subsequent break is not part of the if, and thus it will be invoked unconditionally after the 1st loop iteration is done, so the user will never be able to enter more than 1 number.
your cout statements should have \n or std::endl at the end of them, to print out a line break.
With that said, try something more like this instead:
#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
int rng(){
return (rand() % 12) + 1;
}
int main()
{
srand(time(NULL));
int sum = 0;
char response;
do {
cout << "Would you like to add a number? y or n: ";
cin >> response;
if (response == 'n') {
cout << "Okay thanks, have a good one\n";
break;
}
if (response == 'y') {
sum += rng();
cout << "Okay then, the current sum is " << sum << "\n";
if (sum > 50) {
cout << "Alright the sum has reached 50 that seems like enough\n";
break;
}
}
}
while (true);
}

Answer 2

This line:
int sum = 0
Needs a semi-colon at the end.
Same with these lines:
cout << "Alright the sum has reached 50 that seems like enough"
break
You need to use == instead of = in the condition of the while statement:
while (response == 'y') {
Also, this line:
cout << "Okay then, the current sum is" << +" " << +sum << +rng;
should be
cout << "Okay then, the current sum is" << " " << sum << rng;