Convert int vector to float vector C++

Question

I tried the C cast style as shown below but to no avail

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    std::vector<int> intVec = { 1, 2, 3 };
    std::vector<float> floatVec;
    for (int i = 0; i < intVec.size(); i++)
    {
        float new_num = (float)intVec[i];
        floatVec.push_back(new_num);
    }
        

    for (int i = 0; i < floatVec.size(); i++)
        cout << floatVec[i] << endl;

    return 0;
}

Output in console:

1
2
3

What am I doing wrong for not getting { 1.0, 2.0, 3.0} as a result?

These numbers *are* floats, it's just how the default way of printing floats works. `std::cout << 1.0` would also print `1`. — Yksisarvinen, Nov 30 '20 at 09:34
Alright so that means that the converson is working correctly I did not realize that whitout setting the precision. Thanks! — Yannick, Nov 30 '20 at 09:37
`std::vector floatVec(intVec.begin(), intVec.end());` is more convenient than looping. — molbdnilo, Nov 30 '20 at 09:39
`float new_num = intVec[i];` is sufficient. Casting that value is not necessary. — Pete Becker, Nov 30 '20 at 15:01

score 3 · Accepted Answer · answered Nov 30 '20 at 09:53

Use std::fixed with cout, like this:

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    std::vector<int> intVec = { 1, 2, 3 };
    std::vector<float> floatVec;
    for (int i = 0; i < intVec.size(); i++)
    {
        float new_num = (float)intVec[i];
        floatVec.push_back(new_num);
    }
        

    for (int i = 0; i < floatVec.size(); i++)
        cout << std::fixed << floatVec[i] << endl;

    return 0;
}

Output

1.000000
2.000000
3.000000

If you want to set the decimal precision, you can use std::setprecision

Convert int vector to float vector C++

1 Answers1