Thread: counting in binary

here's how binary works,

00 = 0
01 = 1
10 = 2
11 = 3

we add from right-to-left, if we have 00 we add by 1 which makes 01, and if we add another 1 we cannot go past a 0 or 1 value so we shift the 1 to the left which makes it 10.

You can tell how many possible combinations in a binary set, such as 1 byte can hold by doing POWERS.

1 byte is 8 bits.
0000 0000

2^8 (2 to the 8th power) = 256 so the values are between 0 - 255 or if signed the values are -127 - 128.

<iomanip.h>

has functions for printing out Hex and Decimal formats - not sure - but maybe it also has a binary format function?

In C and C++ you can only directly express literals in decimal, octal, and hex (and ascii). Not binary.

It's stored as binary and calculations are in binary because that's the only thing the computer can understand.

You can also express ten as 012

Here's one way. This example prints the bits of a signed integer in reverse...I'll leave it to you to make improvements that may be necessary...

Code:

int
 set_bit(int * data, int bit)
{
 return *data |= 1 << bit;
}
int
 clear_bit(int * data, int bit)
{
 return *data &= ~(1 << bit);
}
bool
 is_set(int data, int bit)
{
 return data & (1 << bit);
}
char *
 binary(char buff[33], int x)
{
 buff[32] = 0;
    for(int y = 0; y < 32; ++y )
   {
    buff[y] = is_set( x, y ) ? '1' : '0';
   }
 return buff;
}

int
 integer(char buff[33])
{
 int value = 0;
    for(int y = 0; y < 32; ++y )
   {
       if(buff[y] == '1')
      {
       set_bit(&value, y);
      }
   }
 return value;
}


int
 main(){
char buff[33];
char input[50];
int byte4, bit;

 while(byte4 != 0){
 cout << "Enter a value" << endl;
 byte4 = atoi(fgets(input, 50, stdin));
 cout << binary(buff, byte4) << " = ";
 cout << integer(buff) << endl;
 cout << "Enter a bit to set (1-32)" << endl;
 bit = atoi(fgets(input, 50, stdin));
    if(bit && bit < 33)
   {
    --bit;
    cout << binary(buff, set_bit(&byte4, bit) ) << " = ";
    cout << integer(buff) << endl;
   } else cout << "Out of range..." << endl;
 cout << "Enter a bit to clear (1-32)" << endl;
 bit = atoi(fgets(input, 50, stdin));
    if(bit && bit < 33)
   {
    --bit;
    cout << binary(buff, clear_bit(&byte4, bit) ) << " = ";
    cout << integer(buff) << endl;
   } else cout << "Out of range..." << endl;
 }
 return 0;
}

>>Here are some functions that appear to handle any numeric base:
Up to 36 of course. :-)

I'd create a class to deal with binary numbers. Such a class could contain utility functions to convert integers to binary and vice versa. The binary representation of the number could be stored as a string and an int variable could be used for calculations. But, such a class could be somewhat time consuming (at least for me), so I'd only suggest this if you're really going to be working with binary numbers for a considerable amount of time. Just a suggestion.


Hmmm... Ya know what? I think coding a binary class would be fun. Maybe that'll be my next project. Well, if you see questions in the near future about a binary class, don't be suprised.