How to convert an integer to binary stored in array

Question

I know how to convert an integer from decimal to fixed length binary string:

int number = 3;
int toBase = 2;
int length = 8;
Convert.ToString(number, toBase).PadLeft(length, '0')

Output:

00000011

How to assign the individual elements of that binary string to either int (or bool) array, such that after the conversion the array will look like¹:

int[] binary = {0, 0, 0, 0, 0, 0, 1, 1}

or

bool[] binary = {false, false, false, false, false, false, true, true};

^{1. Using the facilities and not trivial for loop with char to int (or bool) type conversions.}

duplicate? stackoverflow.com/questions/1318933/c-sharp-int-to-byte — tym32167
– tym32167, Commented Oct 14, 2016 at 9:43
bool[] binary = Convert.ToString(...).Select(c => c == '1').ToArray(); — Dmitrii Bychenko
– Dmitrii Bychenko, Commented Oct 14, 2016 at 9:45

Dmitrii Bychenko · Accepted Answer · 2016-10-14 09:57:45Z

1

You can add some Linq to represent the string as an array:

string source = Convert.ToString(number, toBase).PadLeft(length, '0');

...

int[] binary = source.Select(c => c - '0').ToArray();

...

bool[] binary = source.Select(c => c == '1').ToArray();

Or you can compute arrays directly:

int[] binary = Enumerable
  .Range(1, length)
  .Select(i => number / (1 << (length - i)) % 2)
  .ToArray();

bool[] binary = Enumerable
  .Range(1, length)
  .Select(i => number / (1 << (length - i)) % 2 == 1)
  .ToArray();

edited Oct 14, 2016 at 9:57

answered Oct 14, 2016 at 9:46

Dmitrii Bychenko

188k20 gold badges178 silver badges231 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Alfie Goodacre · Accepted Answer · 2016-10-14 09:45:19Z

1

If you store the string you have created, for example

string theBinaryString = Convert.ToString(number, toBase).PadLeft(length, '0');
int[] binary = new int[8];
for(int i = 0; i < 8; i++)
{
    binary[i] = int.parse(theBinaryString[i].ToString());
}

Once the loop has finished you will have the array you are looking for, the ToString() is required as selecting from a string as if it was an array returns a char, which cannot be parsed into an int.

answered Oct 14, 2016 at 9:45

Alfie Goodacre

2,7931 gold badge16 silver badges27 bronze badges

Comments

Sergey Kalinichenko · Accepted Answer · 2016-10-14 09:52:05Z

1

You can do it without converting the number to binary string:

var num = 123;
var bits = Enumerable.Range(0, 8).Select(i => (num >> (7-i)) & 1).ToArray();

The idea is to shift the number right sequentially by a decreasing number of positions, and mask off all bits except least significant one.

Demo.

answered Oct 14, 2016 at 9:52

Sergey Kalinichenko

729k85 gold badges1.2k silver badges1.6k bronze badges

2 Comments

Ziezi Over a year ago

Thank you for the answer! That is for int array right?

Sergey Kalinichenko Over a year ago

@Ziezi Yes, this produces an array of ints. If you want an array of chars, add a conditional to Select expression, or add result to '0' to convert an int to char digit.

Dmitrii Bychenko · Accepted Answer · 2016-10-14 10:18:58Z

1

maybe like this;

"1000110101110".ToCharArray().Select(c => c - '0').ToArray()

will give you:

int[13] { 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0 }

edited Oct 14, 2016 at 10:18

Dmitrii Bychenko

188k20 gold badges178 silver badges231 bronze badges

answered Oct 14, 2016 at 9:51

user734028

1,1411 gold badge10 silver badges23 bronze badges

3 Comments

Dmitrii Bychenko Over a year ago

48 - magic number which is a bad parctice; put '0' instead

Dmitrii Bychenko Over a year ago

when reading your code, it is quite unclear what 48 stands for. Put '0', i.e. c => c - '0' to make it evident: current character minus '0'

user734028 Over a year ago

while i kind of get what you are saying I was of the thinking since we are doing programming and the chararray function is being used it should be pretty evident that 48 is an integer being subtracted from c, a character. You can make a edit if you like.

mybirthname · Accepted Answer · 2016-10-14 09:50:14Z

0

int[] intArray = stringNumber.ToCharArray().Select(n => Convert.ToInt32(n)).ToArray();

edited Oct 14, 2016 at 9:50

answered Oct 14, 2016 at 9:46

mybirthname

18.2k3 gold badges35 silver badges59 bronze badges

1 Comment

mybirthname Over a year ago

@viveknuna yep I fixed it. My bad

Collectives™ on Stack Overflow

How to convert an integer to binary stored in array

5 Answers 5

Comments

Comments

2 Comments

3 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

2 Comments

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related