Input floats from command line using streams

[leighman]

Hello There

My first question on this site, here goes:

I am working on a tutorial question and it asks me to write a program that outputs the product of some entered floating point numbers from the command line: This is to be done using streams.
Now in My tutorial book it suggests using the following code:

#include <iostream>
#include <cstdio>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <fstream>
#include <string>
#include <cstdlib>
#include <istream>
using namespace std;
 
int main(  int argc, char* argv[] ) 
{  
 
          int data[20];
          int i, sum;
 
          for(i=1;i<argc-1;i++){
 
              istream cinx(81,argv[i];
 
              cinx>>data[i];
              cout<<data[i];
 
              sum=sum+data[i];
         }
         cout<<"\nsum = "<<sum;
}
 

So I have tried the above code and many different variations until my hair is falling out! - But to no avail as it does not compile, instead I get the error message along the lines of:

" no matching function for call to `std::basic_istream<char, std::char_traits<char> >::get(char**&, int)"

Any suggestions would be much appreciated...

Regards

leigh

[weaknessforcats]

This code:

for(i=1;i<argc-1;i++){
 
     istream cinx(81,argv[i];
etc...

is a problem.
First, argc is the number of command line argumen ts and not the number of strings in the argv array.
Second, you check for the end of the argv array by looking for a string that contains only two null characters.
Third, you don't need to use cin on argv since you already have the address of the array. All you have to do is process it.

Unless...
the object is for the user to enter floats from the keyboard as the program runs. Then you would use cin.