C++ while loops

hi every one,
im working on a program to convert the binary number system to the decimal one. I have the code yet im wondering if it a while loop can be used instead of a for loop. i have major problems trying to work out for loops, stupid me!

Code:

#include <iostream>
#include <cmath>
usingnamespace std;
void bintodec(int binarynumber, int& decimal, int& weight);
int main ()
{
	int decimalnum;
	int binarynum;
	int bitweight;
	int digit;
	int weight;
	decimalnum = 0;
	bitweight = 0;
	cout<<"Please enter the number of digits you will be using: ";
	cin>>digit;
	cout<<"Enter number in binary: ";
	cin>>binarynum;
	
	bintodec(binarynum, decimalnum, bitweight);
	cout<<"Binary "<<binarynum<<" = " << decimalnum << " decimal"<<endl;
	return 0;
}
void bintodec(int binarynumber, int& decimal, int& weight)
{
	int bit;
	int digit;
	for(int weight; weight <= digit; weight++)
	{
		bit = binarynumber % 10;
		decimal = decimal + bit * static_cast<int>(pow(2, weight));
		binarynumber = binarynumber /10;
		
		bintodec (binarynumber, decimal, weight);
	}
}

Here is the code, thanks so much for any1 who helps me.

Cheers
Becki

 

Without reading your posted code, he's the most basic difference between FOR and WHILE loops:

FOR loops have control over a variable. You use this if your have an incremental loop. That is, if you need to loop through a SET (of objects, indexes in an array, etc).

WHILE loops have no control over a variable. They instead simply continue to loop until the condition specified is no longer met.

Here is an example of a FOR and WHILE loop doing the same thing

Code:

for ( int i = 0; i < 10; i ++ )
{
  // Do whatever
}

// or...

int i = 0;
while ( i < 10 )
{
  // Do whatver
  i++;
};

As far as converting binary to decimal.. Binary numbers CANNOT be decimal.I don't quite understand what you are trying to achieve here in your code. I can understand a binary text string like "1101" being converted to an integer value of 13, but your code doesn't seem to be doing that.

 

Thanks and I figured out the difference of the loops. I am practising them now. Thanks for the help Essial.

 

Code:

for ( int i = 0; i < 10; i ++ )
{
  // Do whatever
}

// or...

int i = 0;
while ( i < 10 )
{
  // Do whatver
  i++;
};

// or...

int i=0;

start:

// Do whatver
i++;

if ( i < 10 )
  goto start; 

// or...

run( 10 );
...
void run (int a)
{
  if ( a > 0)
    {
       // Do whatver
       run(a-1);
    }
 
}

// or...

int i=0;

do{

// Do whatver
i++;

}while(i<=10);

 

how to creat c++ programme that i can write the numbers from 1 to 10, and write even on the top of even numbers or odd on the top of odd numbers ,, with useing these orders \t, \n, if or while.

the answer it should be lie this
odd even
1 2
3 4
5 6
7 8
9 10

pls, pls, pls help fast

 

Code:

//.............
#include<iostream.h>

void main()
{
  int a;
  int b;
  cout<<" A < B \n  A :";
  cin>>a;
  cout<<" B :";
  cin>>b;
  if(a % 2 ==0)
   cout<<' '<<'\t';
  while( b >= a )
   {
     cout<<a;
      if(a % 2 ==0)  { cout<<'\n'; }
        else  {  cout<<'\t';  }
        a++;
   } 
}


//..............

for EX:

Code:

A : 5
B : 10

5----6
7----8
9----10
 

----------

A = 4
B = 11

-----4
5----6
7----8
9----10
11----