how can i get this
convert an array to MPH if data represents KPH
equation:multiply by 5/8

Start by making a program that will at least compile, anything is better than nothing.

#include <iostream>

int main() {
   return 0;
}

Now, heres an example of how to convert a single variable to MPH using the formula given.

#include <iostream>

int main() {
   double KPH = 50;
   double MPH = KPH * (5.0 / 8.0);
   return 0;
}

And now that you can do that, try making an attempt at the rest by yourself. Although admitedly, I don't quite understand what you mean by "convert an array to MPH if data represents KPH"... is that an array of numbers you need to convert? or a string..? :icon_cheesygrin: