C++ Randomly select from string array - c++

Question

I'm trying to devise a function that randomly selects three of the five strings and displays them on the screen. Here's what I have so far. It runs but nothing prints to the screen.
#include "BoxOfProduce.h"
#include <iostream>
#include <string>
#include <ctime>
#include <cstdlib>
#include <vector>
#include <memory>
using namespace std;
BoxOfProduce::BoxOfProduce()
:choices{""}, bundles{""}
{
}
vector<string> BoxOfProduce::randomize()
{
srand(time(0));
string choices[] = {"Broccoli", "Tomato", "Kiwi", "Kale", "Tomatillo"};
vector<string> random;
for(int i = 0; i < 3; i++)
{
random.push_back(choices[rand() % 5]);
}
return random;
}
#ifndef BOXOFPRODUCE_H
#define BOXOFPRODUCE_H
#include <iostream>
#include <string>
#include <vector>
#include <memory>
using namespace std;
class BoxOfProduce
{
public:
BoxOfProduce();
string getBundles();
void setBundles(string b);
vector<string> randomize();
private:
string bundles[3];
const string choices[5];
string random;
};
#endif // BOXOFPRODUCE_H
#include <iostream>
#include "BoxOfProduce.h"
#include <string>
#include <ctime>
#include <cstdlib>
#include <vector>
#include <memory>
using namespace std;
int main()
{
srand(time(0));
BoxOfProduce bo;
bo.randomize();
auto vector<string> randomResult = bo.randomize();
for (const auto& result : randomResult){
cout << result << endl;
}
}
I have updated my code now and still no print output. Although I am getting an error:
error: range-based 'for' loops are not allowed in C++98 mode
I have never worked with auto before. So any help on this would be appreciated.

Answer 1

Your code should not compile. g++ emits the following error:
return random;
error: could not convert ‘random’ from ‘long int (*)()throw ()’
The random variable is local to your for-body. You should give it a greater scope:
string random;
for(int i = 0; i < 3; i++)
{
random = choices[rand() % 5];
}
return random;
To produce the 3 results, you need to return a vector of string like
#include<ctime>
#include<cstdlib>
#include<string>
#include<memory>
#include<vector>
#include<iostream>
using namespace std;
std::vector<string> randomize()
{
srand(time(0));
string choices[] = {"Broccoli", "Tomato", "Kiwi", "Kale", "Tomatillo"};
std::vector<string> random;
for(int i = 0; i < 3; i++)
{
random.push_back(choices[rand() % 5]);
}
return random;
}
int main()
{
srand(time(0));
randomize();
std::vector<string> randomResult = randomize();
for (std::vector<string>::const_iterator iter = randomResult.begin(), iterEnd = randomResult.end();
iter != iterEnd; ++iter)
cout << *iter << endl;
return 0;
}

Answer 2

The scope of string random is only inside the for loop in your code.
try this:
string BoxOfProduce::randomize()
{
srand(time(0));
string choices[] = {"Broccoli", "Tomato", "Kiwi", "Kale", "Tomatillo"};
string random = "";
for(int i = 0; i < 3; i++)
{
random = choices[rand() % 5];
}
return random;
}
int main()
{
srand(time(0));
BoxOfProduce bundle1;
bundle1.randomize();
cout << bundle1.randomize() << endl;
}

Answer 3

The code you provided shouldn't even compile. Try this:
string BoxOfProduce::randomize()
{
srand(time(0));
string choices[] = {"Broccoli", "Tomato", "Kiwi", "Kale", "Tomatillo"};
string random;
for(int i = 0; i < 3; i++)
{
random = choices[rand() % 5];
}
return random;
}
int main()
{
srand(time(0));
BoxOfProduce bundle1;
bundle1.randomize();
cout << bundle1.randomize() << endl;
}
The braces { } define a scope. After that scope, the variables you define inside it are destroyed. So you should define that variable before you start that scope.
Probably the reason it compiled is that you already have another variable string random inside the body of the class BoxOfProduce. So you either define that string random outside the scope, like I did, or you just remove the string before random, and then the compiler will use the variable from the class body.