easy and fast way to convert an int to binary?
C#C# Problem Overview
What I am looking for is something like PHPs decbin
function in C#. That function converts decimals to its representation as a string.
For example, when using decbin(21)
it returns 10101
as result.
I found this function which basically does what I want, but maybe there is a better / faster way?
C# Solutions
Solution 1 - C#
var result = Convert.ToString(number, 2);
– Almost the only use for the (otherwise useless) Convert
class.
Solution 2 - C#
Most ways will be better and faster than the function that you found. It's not a very good example on how to do the conversion.
The built in method Convert.ToString(num, base)
is an obvious choice, but you can easily write a replacement if you need it to work differently.
This is a simple method where you can specify the length of the binary number:
public static string ToBin(int value, int len) {
return (len > 1 ? ToBin(value >> 1, len - 1) : null) + "01"[value & 1];
}
It uses recursion, the first part (before the +) calls itself to create the binary representation of the number except for the last digit, and the second part takes care of the last digit.
Example:
Console.WriteLine(ToBin(42, 8));
Output:
00101010
Solution 3 - C#
int toBase = 2;
string binary = Convert.ToString(21, toBase); // "10101"
Solution 4 - C#
To have the binary value in (at least) a specified number of digits, padded with zeroes:
string bin = Convert.ToString(1234, 2).PadLeft(16, '0');
The Convert.ToString does the conversion to a binary string.
The PadLeft adds zeroes to fill it up to 16 digits.
Solution 5 - C#
This is my answer:
static bool[] Dec2Bin(int value)
{
if (value == 0) return new[] { false };
var n = (int)(Math.Log(value) / Math.Log(2));
var a = new bool[n + 1];
for (var i = n; i >= 0; i--)
{
n = (int)Math.Pow(2, i);
if (n > value) continue;
a[i] = true;
value -= n;
}
Array.Reverse(a);
return a;
}
Using Pow instead of modulo and divide so i think it's faster way.