converting from binary to decimal and vice versa

[revenge2]

hello there, I am working on a small c program that automatically detects whether the input given is a decimal number or a binary number and coverts accordingly.

what is the best way to convert a binary number to a decimal number and a decimal number to a binary number.

i found this to be the easiest when converting from binary to deicmal
http://www.wikihow.com/Convert-from-Decimal-to-Binary

but my program doesnt work..?

/*decimal to binary*/
#include <stdio.h>
int main() {
	int dec;
	int hold=0;
	printf("decimal number : ");
	scanf("%d",&dec);
	
	hold=dec%2;
	
	while (hold!=1){
		if (hold == 0){
			printf("0");
		}else if(hold >1){
			printf("1");
		}else{
			printf("1");
		}
		hold=hold%2;
	}
}

what have i done wrong?

[Hiroshe]

You don't have any divide's in there. You can't just use modulo for the whole thing. Also, you forgot to read the number backwards.

[ambarisha.kn]

/*decimal to binary*/
#include <stdio.h>

void printBinary(const unsigned char val) {

  for(int i = 7; i >= 0; i--)

    if(val & (1 << i))

     printf("1");

    else

      printf("0");
  printf("\n");

} 

int main() {
	int dec;
	int hold=0;
	printf("Integer number : ");
	scanf("%d",&dec);
	printBinary((unsigned char)dec);	
}

[revenge2]

hmmm why doesn't this work?

#include <stdio.h>

void bin_c(int x);

int main(){
	int x;
	printf("Enter a number:");
	scanf("%d",x);
	
	bin_c(x);
	return 0;
}

void bin_c(int x){
	
	if (x == 1){
		printf("1");
	}
	
	while (x!=1){
		int y;
		y=x/2;
		if (y == 0){
			printf("0");
		}
		if (y > 1){
			printf("1");
		}
		if (y == 1){
			printf("1");
		}
		bin_c(y);
	}
	
}

i know i have to reverse the order but this doesnt work why is this?

[WaltP]

To get a binary value from a decimal value v = val %2; -- v will contain the value of the ones digit. Then, after you get the digit, remove it to get the next digit: v = val /2; Loop until val is 0.

[akirue09]

could you pls. do me a program that converting a binary to decimal or decimal to binary with a simple codes in turbo c, which i can easily understand.. for example i will enter an number 1 then it will be automatically to convert it to its binary value. thank u! i will wait for your help! pls. help me..