Question

Not very good at debugging yet but I’m getting a few errors. A few expected ‘(‘ ‘)’ and ‘;’
Also ‘else’ without a previous ‘if’, no match for ‘operator>>’ in cout

I know this is easy, but still trying to get my foot in the door. Thanks 🙂

#include <iostream>
#include <cstdlib>
using namespace std;

int main()   // guess number game
{
    int x;
    cout >> "Please enter a number\n";
    getline(cin x);
    int y = rand();

    while x != y
    {

        if x < y;
           cout >> "Go higher";
        else;
           cout >> "Go lower";
    }


}

Answer 1

cout >> "Please enter a number\n";

This is wrong, std::ostreams only provide the operator<< to insert formatted data. Use cout << "Please enter a number\n"; instead.

getline(cin x);

First, you’re missing a ,, since getline needs two or three arguments. But since x is an integer and not a std::string it is still wrong. Think about it – can you store a text line inside of an integer? Use cin >> x instead.

int y = rand();

While this doesn’t seem wrong there’s a logical error. rand() is a pseudo random number generator. It uses a seed as start value and some kind of algorithm (a*m + b). Thus you have to specify a start value, also called seed. You can specify this by using srand(). The same seed will result in the same order of numbers, so use something like srand(time(0)).

while x != y
if x < y;

Use parenthesis. And drop the additional ;. A stray semicolon ; in your program resembles the empty expression.

EDIT: Working code:

#include <iostream>
#include <cstdlib>
#include <ctime>

int main(){
    int x;
    int y;
    srand(time(0));
    y = rand();
    std::cout << "Please enter a number: ";
    do{
        if(std::cin >> x){
            if(x < y)
                std::cout << "Go higher: ";
            if(x > y)
                std::cout << "Go lower: ";    
        }
        else{
            // If the extraction fails, `std::cin` will evaluate to false
            std::cout << "That wasn't a number, try again: ";
            std::cin.clear(); // Clear the fail bits
        }
    }while(x != y);
    std::cout << "Congratulations, you guessed my number :)";

    return 0;
}