CODEWITHSUNDEEP
c++vectorreturn
Jenny
Jenny

Reputation: 121

Passing a vector by reference

#include <iostream>
#include <vector>

void init()
{       
    std::vector<double> b;
    b.push_back(10);
    return;
}

double mean(double *array, size_t n)
{
    double m=0;
    for(size_t i=0; i<n; ++i)
    {
        m += array[i];
    }
    std::cout<<*array<<std::endl;
    return m/n;
}

int test(int *b)
{
    int dist;
    dist=b[0];
    return dist;
}

int main()
{
    int x=0;
    int y=0;
    //double a[5]={1, 2, 3, 4, 5};
    std::vector<double> a;
    a.push_back(1);
    a.push_back(2);
    a.push_back(3);
    a.push_back(4);
    a.push_back(5);
    std::cout<<mean(&a[0], 5)<<std::endl;    // will print 3
    init();
    y=test(&b[0]);
    std::cout<<y<<std::endl;
    return 0;
}

I am trying to check if I can initialize vector "b" in "init" function and retrieve value in "test" function to finally return as "y" in main function. Is this even possible? It is just a test code to explore this possibility.

Upvotes: 1

Views: 77

Answers (1)

M.M
M.M

Reputation: 141658

Maybe you want:

std::vector<double> init()
{       
    std::vector<double> b;
    b.push_back(10);
    return b;
}

and then in main:

auto b = init();
y = test( &b.at(0) );

When calling mean. get the size as a.size() instead of hardcoding the 5. And pass a.data() instead of &a[0], then it won't crash if the vector is empty.

Upvotes: 2

Related Questions