How to Pass Decimal Value as Argument Correctly

Question

I have this:

double myDecimal = static_cast<double>(atoi(arg_vec[1]));
cout << myDecimal << endl;

But why when I pass the argument like this:

./MyCode 0.003

It prints 0 instead of 0.003.

Answer 1

atoi() converts to an integer, you want atof(), which converts to a double

Answer 2

atoi() converts to integer. You want atof().

Or you could use strtod().

Answer 3

Since you're using C++, you can also use stringstreams:

istringstream ss(arg_vec[1]);
double d;
ss >> d;

Answer 4

double d = boost::lexical_cast<double>("0.003");