Problem with switching function prototype to another type

[jimmy107]

Hello, I have a question about strings and switching them to arrays.
This is my code:

#include<iostream>
#include<string>
using namespace std;

int bin2dec(const string binarystring);    // Declaration of bin2dec prototype with one string parameter



int main()
    {
    
        cout << "Enter Q to terminate program.\n";
        
        while(true)
    {
        string binary;
        cout <<  "Enter a binary number: ";    //prompt user to enter binary string
        cin >>  binary;
        
        if (binary == "Q")
        {
            break;
        }
        
        cout  <<  "The decimal equivalent of: "  <<  binary  <<   "  is: "   <<   bin2dec(binary)  <<  endl;
        // output of the binary string and its decimal equivalent
    }
    }

int bin2dec(const string binarystring)   // Function definition with one string parameter
{
    unsigned int result = 0 ;       // creating int result to return to main function
    

    for( char c : binarystring ) // for each character in the binary string
    {
        result *= 2 ; // shift result left by one binary digit
        if( c == '1' ) result += 1 ; // add one if the bit is set
    }
    
    return result ;     // Returning result to main function
    
}

Right now the code is in the form of a 'const string binarystring' and were supposed to be able to use 'const char binarystring[]' and for some reason whenever i try to switch it i run into problems when referencing the main function to the int bin2dec(...) function.

I wanted to know if theres a simple way to switch the prototype to an array type of function with [] without changing the entire code. Thanks!

[giblit]

Even left JLBorges comments :P
As far as the assignment it seems as if they want you to read in a bunch of strings to an array then pass that to the convert.

Maybe they want something like:

std::size_t binaries;
std::cout << "Please enter the number of binary numbers: ";
std::cin >> binaries;
std::cin.ignore(1024, '\n'); //remove new line buffer
//so that way if the user enters their binaries like:
//0101 0000
//instead of
//01010000
//it will work

std::string *binaryNumbers = new std::string[binaries];
for(int i = 0; i < binaries; ++i)
{
    std::cout << "Please enter binary number " << i+1 << ": ";
    std::getline(std::cin, binaryNumbers[i]);
}

bin2dec(binaryNumbers);

Or maybe they want an array of characters instead of std::string?

[jimmy107]

the complete question is this:

Write a function that returns a decimal number from a binary string. The function header as follows int bin2dec(const char binarystring[]).

for example, binarystring 10001 is 17.

I think they want the array of characters.

Thanks for responding!

[giblit]

int bin2dec(const string& binarystring[]) That is a very odd prototype.

[jimmy107]

oh wait lol I'm so sorry its (const char binarystring[])

[Daleth]

I'm pretty sure your original program is correct. Does the assignment really say int bin2dec(const string& binarystring[])? Otherwise, the array version makes little sense... Although...

void bin2dec(const string binarystring[], int dest[], std::size_t num){
    while(num-- > 0)
        dest[num] = bin2dec(binarystring[num]);
}

:V

Edit:
Did not see your last post...

[jimmy107]

Sorry my fault, I edited my previous posts!

[giblit]

So you are still having problems? You can either 1) read into a char array or 2) use std::string.c_str();[/code] http://www.cplusplus.com/reference/string/string/c_str/