How to do something like: "Your number is " + number " ." in C++? - c++

Question

I recently started C++, moving from JavaScript, so I'm a little bit confused.
I'm trying to make a number guessing game, and my actual error is something like:
main.cpp:14:67: error: invalid operands of types ‘const char*’ and ‘const char [2]’ to binary ‘operator+’
cout << "Perfect, now your playing with numbers up to " + range + "."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
$ g++ main.cpp
main.cpp: In function ‘int main()’:
main.cpp:14:67: error: invalid operands of types ‘const char*’ and ‘const char [2]’ to binary ‘operator+’
cout << "Perfect, now your playing with numbers up to " + range + "."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
I have no idea if it helps, but I'm going to attach my code below:
#include <iostream>
using namespace std;
void startGame(int random);
int generateNo(int range);
int main() {
int range;
cout << "WELCOME TO NUMBER GUESSING GAME!" << endl;
cout << "The calculator is going to generate a random number and you'll have to guess it!" << endl;
cout << "Please enter the range of numbers you want to play (ex: 10)" << endl;
cin >> range;
int solution = generateNo(range);
cout << "Perfect, now your playing with numbers up to " + range + "."
cout << "GOOD LUCK :)" << endl;
startGame(solution);
return 0;
}
int generateNo(int range) {
return rand() % range + 1;
}
void startGame(int random) {
int inputNo;
cin >> inputNo;
for( int a = 0; ; a++) {
if(inputNo == random) {
cout << "Congrats! You've guessed the number!" << endl;
break;
} else if(inputNo > random) {
cout << "Hooolly! WHAT'S with this giant number" << endl;
startGame(random);
break;
} else {
cout << "Good number, but had your little brain considered to make it bigger!?" << endl;
startGame(random);
break;
}
}
}

Answer 1

You can chain calls to <<:
cout << "Perfect, now your playing with numbers up to " << range << ".";
If you want to first build a string (no reason to do that here), you first need to build a string:
std::string text = std::string{"Perfect, now ..."} + std::to_string(range) + ".";
std::cout << text;
In your code you are trying to add a string literal (type is char[N]) with an integer. There is no operator+ to concatenate an integer to a string literal.

Answer 2

C++ doesn't overload the + operator between all the arbitrary types, and doesn't implicitly convert everything to strings when you try to print it out. Luckily, for all the built-in types, you could just write them to the output stream using the << operator (and override it for your own types):
cout << "Perfect, now your playing with numbers up to "
<< range // Note the use of "<<" and not of "+"
<< "."
<< "GOOD LUCK :)"
<< endl;