convert word to binary

How can I convert a word such as 'A' to the number represented in ASCII ? Another question is how can i convert a decimal number to binary number? Is any function in c allows us to do that?

Thanx for any help

int num;
num = (int) 'A';

To convert a int to a binary string. One way is function itoa(), if your compiler has it.

Code:

---

#include <stdlib.h>
int main(void)
{
  int num = 255;
  char str[33];
  itoa(num,str,2);
}

---

And here's a clever function to print in binary that someone posted:

Code:

---

void printbits( int x )
{
  int y;
  for( y = 31; y >= 0; y-- ) printf("%d",(x&(1<<y))?1:0);
      printf("\n");
}

---

will this also work?
int i;
i='A';
printf("%d",i)//prints ASCII value of 'A'

yes

>will this also work?
Yes

big thanx for you guys!!
now another question is how can I mask those binary #
for ex:

111000101
if i want shift right to 3, it will become
101111000,
just like what shr does in assembly language, but how can i do that in c?
is any function allows us to do that?

X>>Y (Shifts X's bits Y steps to the right)
X<<Y (Shifts X's bits Y steps to the left)

asm
{
DW BINARY NUMBER = "=x"
}

As long as you can find a way of replacing x with the number, that works...

really big thanks to you all!!
my last two questions are

1. how can i "and" or "or" those binary in c#?

ex:

Code:

---

            1100110
  (and)    0011100
----------------------
            0000100

---

2. how can i convert binary # back to decimal #?
or where can i find the tutorial web site about them?

Thanx again

>1. how can i "and" or "or" those binary in c#?

Well in C:

& - binary AND
| - binary OR

I don't know about C#, but I guess it's the same as in C.

>2. how can i convert binary # back to decimal #?
>or where can i find the tutorial web site about them?

Binary number

bn ... b3 b2 b1 b0

Decimal

2^0 b0 + 2^1 b1 + 2^2 b2 + ... + 2^n bn

Not again!!!

Here´s my code; it´s my first real C-program:

Code:

---

#include <stdio.h>
#include <string.h>

#define PUFFER 256


void asctobin(void); /* converts ASCII-characters into binary digits */
void bintoasc(void); /* converts binary digits into ASCII characters */

unsigned char bin[]={1,2,4,8,16,32,64,128};

int main(void)
{
        char chose;

        for(chose=0;chose<40;chose++,printf("\n")) ; /* clear screen */

again:
        printf("Enter \'A\' to convert ASCII to binary or \'B\' to convert binary into ASCII: ");
        scanf("%c",&chose);
        if(chose=='A' || chose=='a') asctobin();
        else
        {
                if(chose=='B' || chose=='b') bintoasc();
                else{
                        rewind(stdin); /* back to the begin of stdin; if more then one character was entered */
                        goto again;
                } /* only accepts 'A','a','B' and 'b' as inputs */
        }

        return 0;
}


void asctobin(void)
{
        char string[MAX],c;
        int count,len;

        printf("Enter string (max length: 255 characters): ");
        rewind(stdin); /* back to the begin of stdin */
        fgets(string,PUFFER-1,stdin);

        len=strlen(string);

        for(;len>0;len--) /* as often as the value for the length of the inputed string */
        {
                c=*string; /* the character string points to at the moment */
                for(count=7;count>=0;count--)
                {       
                        if(c>=bin[count])
                        {
                                printf("1");
                                c-=bin[count];
                        }else
                        printf("0");
                }
                *string++;
                printf(" ");
        }
}


void bintoasc(void)
{
        char string[MAX],c;
        int count=7,len;


        printf("Enter digits (max 255):");
        rewind(stdin); /* back to the begin of stdin */
        fgets(string,PUFFER-1,stdin);

        len=strlen(string);

        for(;len>0;len--) /* as often as the value for the length of the inputed string */
        {
                if(*string=='1')
                {
                        c+=bin[count], --count;
                }else
                if(*string=='0') --count;

                if(count==0)
                {
                        printf("%c",c);
                        count=7;
                        c=0;
                }

                *string++;
        }
}

---

klausi

thanx you all very much, but i still have questions about masking
number
I wrote a small program:

Code:

---

#include <stdlib.h>
int main(void)
{
  unsigned char i='a';
  unsigned char b='c';
  char str[33];
  i='a'+'c';
  printf("%d\n",i);
  itoa(i,str,2);
  printf("%s\n", str);
  i << 3;
  printf("%d\n",i);  //still can't shift
  i & 3;
  printf("%d\n",i); // still can't and
  return 0;
}

---

I can't mask the number
cna anyone tell me what's wrong with it?
really appreciate

Quote:

---

Originally posted by Supra
i << 3;
i & 3;
I can't mask the number
cna anyone tell me what's wrong with it?
really appreciate

---

That is the same as typing this somewhere in your code:

1+6;

As you see, it does nothing. You have to store your result somewhere:

i=(i << 3); and i=(i & 3);

Or in an even simplier way:

i <<= 3; and i &= 3;

Good luck!

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