Storing multiple integers in a string [closed] - c++

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I am trying to store 5 integers into a string, but I am having trouble. Here is the code:
for (int a = 0; a < 5; a++)
{
string ans;
int number;
int num;
number = rand() % 9 + 1;
cout << number << " ";
num = number;
to_string(num);
ans =+ num;
}
Essentially, I would like "ans" to be something along the lines of "12345" but when I run it, it either doesn't show anything or shows 5 boxes with question marks inside of them. Any help?

Answer 1

You can do something like this:
string ans;
int number;
for (int a = 0; a < 5; a++){
number = rand() % 9 + 1;
ans += to_string(number);
}
cout << ans;

Answer 2

to_string() returns a string.
You can simply try doing:
ans += to_string(num);
Or, better way to write your code for improved readability is to use a temporary string variable instead of an int num to store the number.
string temp;
string ans;
for (int a = 0; a < 5; a++)
{
//string ans;
int number;
//int num;
number = rand() % 9 + 1;
cout << number << " ";
//num = number;
temp = to_string(number);
ans += temp;
}
You do not want to declare your string ans inside the for loop because every time the loop runs, you ans will not hold the previous value anymore as it gets declared again.

Answer 3

There are a number of problems with your code.
you are declaring ans inside the loop, so it is created and destroyed on each loop iteration. If you want the loop to append 5 numbers to ans, you have to declare it outside of the loop instead.
std::to_string() outputs a new std::string as its return value. It does not "magically" turn the input value into a string type, like your code is assuming. You are not appending the returned string to ans at all.
=+ is not a valid append operator. It is interpreted as separate operators = and +. std::string does not have a = operator that takes an int as input, and does not have a unary + operator. You need to use the += operator instead.
Try this:
#include <string>
#include <iostream>
std::string ans;
for (int a = 0; a < 5; ++a)
{
int number = ...
...
ans += std::to_string(number);
}
// use ans as needed...
Alternatively, use std::ostringstream instead of std::to_string():
#include <string>
#include <sstream>
#include <iostream>
std::ostringstream oss;
for (int a = 0; a < 5; ++a)
{
int number = ...
...
oss << number;
}
std::string ans = oss.str();
// use ans as needed...
With that said, you are clearly using C++11 (when std::to_string() was introduced) or later, so you should be using a C++ random number generator instead of the one from C, eg:
#include <random>
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(1, 9);
for (int a = 0; a < 5; ++a)
{
int number = dis(gen);
...
}