Convert decimal to binary in C

Question

I am trying to convert a decimal to binary such as 192 to 11000000. I just need some simple code to do this but the code I have so far doesn\'t work:

void de         


        

Answer 1

So... did you check the output of your code to understand why it doesn't work?

So iteration 1 of your loop:
value = 192
i = 4
output[i] = (11000000 & 1) + '0' = 0 + 48 = 48 (char `0`)

Iteration 2 of your loop:
value = 96
i = 3
output[i] = (1100000 & 1) + '0' = 0 + 48 = 48 (char `0`)

Iteration 3 of your loop:
value = 48
i = 2
output[i] = (110000 & 1) + '0' = 0 + 48 = 48 (char `0`)

Iteration 4 of your loop:
value = 24
i = 1
output[i] = (11000 & 1) + '0' = 0 + 48 = 48 (char `0`)

Iteration 5 of your loop:
value = 12
i = 0
output[i] = (1100 & 1) + '0' = 0 + 48 = 48 (char `0`)

Final string: "00000"  and you wanted: "11000000"

See anything wrong with your code? Nope. Neither do I you just didn't go far enough. Change your output/loop to:

output[8] = '\0';
for (i = 7; i >= 0; --i, value >>= 1)

And then you'll have the correct result returned.

I would recomend just a more general approach, you're using a fixed length string, which limits you to binary numbers of a certian length. You might want to do something like:

loop while number dividing down is > 0
count number of times we loop
malloc an array the correct length and be returned