returning multiple values in value returning function - c++

Question

I want to write a program that counts the number of times a certain vowel appears in a string but each value must be returned.
int vowel_count(string);
int main()
{
string str;
cout << "Enter a string";
cin >> str;
// Calling funtion:
vowel_count(str);
}
int vowel_count(string var)
{
int sum_a = 0;
int sum_e = 0;
int sum_i = 0;
int sum_o = 0;
int sum_u = 0;
for (int j = 0; j < var.length(); j++)
{
if (Var.at(j) == 'a')
sum_a++;
if (Var.at(j) == 'e')
sum_e++;
if (Var.at(j) == 'i')
sum_i++;
if (Var.at(j) == 'o')
sum_o++;
if (Var.at(j) == 'u')
sum_u++;
}
return sum_a;
return sum_e;
return sum_i;
return sum_o;
return sum_u;
}
Everytime I return , the program terminates, I would like to know how to I overrun the function of return.

Answer 1

You can use std::tuple to return multiple values from a function. Then you can either use std::get or std::tie to get at the values in the tuple. This avoids having to define a struct/class simply for the purpose of returning a result from your function vowel_count().
Since you tagged your question with C++14, I assume you haven't got C++17. However, with C++17 you can use structured bindings to extract the values instead.
For C++11/C++14:
#include<iostream>
#include<tuple>
using TupleVowel = std::tuple<int, int, int, int, int>;
TupleVowel vowel_count(std::string var)
{
int sum_a = 0;
int sum_e = 0;
int sum_i = 0;
int sum_o = 0;
int sum_u = 0;
for (int j = 0; j < var.length(); j++)
{
if (var.at(j) == 'a')
sum_a++;
if (var.at(j) == 'e')
sum_e++;
if (var.at(j) == 'i')
sum_i++;
if (var.at(j) == 'o')
sum_o++;
if (var.at(j) == 'u')
sum_u++;
}
return std::make_tuple(sum_a, sum_e, sum_i, sum_o, sum_u);
}
int main(void)
{
int sum_a = 0;
int sum_e = 0;
int sum_i = 0;
int sum_o = 0;
int sum_u = 0;
std::tie(sum_a, sum_e, sum_i, sum_o, sum_u) = vowel_count("hello world");
std::cout << "sum_a = " << sum_a << ", sum_e = " << sum_e << ", sum_i = " << sum_i << ", sum_o = " << sum_o << ", sum_u = " << sum_u << std::endl;
}
Live demo.
You can also use std::get() with the index of the element like this without having to 'tie' the tuple elements to variables:
auto tup = vowel_count("hello world");
std::cout << "sum_a = " << std::get<0>(tup) << ", sum_e = " << std::get<1>(tup) << ", sum_i = " << std::get<2>(tup) << ", sum_o = " << std::get<3>(tup) << ", sum_u = " << std::get<4>(tup) << std::endl;
In C++17, you can just do:
auto [sum_a, sum_e, sum_i, sum_o, sum_u] = vowel_count("hello world");
Live demo.

Answer 2

When the type of the returned variable is the same, you can use a std::array (also std::vector or std::deque, but, given that the number of the returned variable is fixed, I suppose std::array is preferable)
I mean, something as follows
#include <array>
#include <iostream>
auto vowel_count (std::string var)
{
int sum_a = 0;
int sum_e = 0;
int sum_i = 0;
int sum_o = 0;
int sum_u = 0;
for ( auto const & ch : var )
if ( ch == 'a') ++sum_a;
else if ( ch == 'e') ++sum_e;
else if ( ch == 'i') ++sum_i;
else if ( ch == 'o') ++sum_o;
else if ( ch == 'u') ++sum_u;
return std::array<int, 5u>{ sum_a, sum_e, sum_i, sum_o, sum_u };
}
int main()
{
std::string str;
std::cout << "Enter a string";
std::cin >> str;
auto vc = vowel_count(str);
std::cout << "a: " << vc[0] << std::endl;
std::cout << "e: " << vc[1] << std::endl;
std::cout << "i: " << vc[2] << std::endl;
std::cout << "o: " << vc[3] << std::endl;
std::cout << "u: " << vc[4] << std::endl;
}
Observe that, starting from C++17, you can use structured bindings, exactly as suggested from jignatius in the std::tuple based solution.
auto [sum_a, sum_e, sum_i, sum_o, sum_u] = vowel_count(str);
std::cout << "a: " << sum_a << std::endl;
std::cout << "e: " << sum_e << std::endl;
std::cout << "i: " << sum_i << std::endl;
std::cout << "o: " << sum_o << std::endl;
std::cout << "u: " << sum_u << std::endl;

Answer 3

The answers above are way too complicated.
The easiest solution is a simple struct.
struct VowelResult {
int a;
int e;
int i;
int o;
int u;
};
VowelResult func () {
int sumA = 0;
int sumE = 0;
int sumI = 0;
int sumO = 0;
int sumU = 0;
//your code goes here...
return {sumA,sumE,sumI,sumO,sumU}; // order matters here
// alternatively:
// VowelResult res{};
// res.a = sumA;
// res.e = sumE;
// and so on...
// return res;
// alternatively alternativey you can simply use the struct directly to store the sums
}