Convert.ToString() to binary format not working as expected

Question

int i = 20;
string output = Convert.ToString(i, 2); // Base2 formatting
i = -20;
output = Convert.ToString(i, 2);

Value   Expected                       


        

Answer 1

int value = 31;
string binary = Convert.ToString(value, 2);
Console.WriteLine(binary.PadLeft(8, '0'));          // Outputs "00011111"