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Converting Strings to Numbers

Required header:  #include <stdlib.h>

It may be necessary to convert numbers stored in strings to a numeric data type.  Here are three functions that will enable you  to perform this task:

1. atoi(s) pronounced "ASCII to integer"
converts character s to an integer. 

apstring starship = "1701 D Class";
int j = atoi(starship.c_str());
cout<<j;     //
will print 1701

apstring address = "RR 3 Box 448";
int j = atoi(address.c_str());
cout<<j;     //
will print 0


2. atol(s) converts character s to a long integer
3. atof(s) converts character s to a floating point number.




The apstrings will need to be converted to traditional C++ strings for these functions.
(use string.c_str())


Remember, numbers stored in strings must be converted to a numeric type (such as int) before they can be used in calculations.