Use bitwise OR to make a number odd. : Bitwise OR « Data Type « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Data Type
3. Bitwise OR

using System; 
 
class Example {  
  public static void Main() { 
    ushort num;  
    ushort i;     
 
    for(i = 1; i <= 10; i++) { 
      num = i; 
 
      Console.WriteLine("num: " + num); 
 
      num = (ushort) (num | 1); // num | 0000 0001 
 
      Console.WriteLine("num after turning on bit zero: " 
                        +  num + "\n");  
    } 
  } 
}

num: 1
num after turning on bit zero: 1

num: 2
num after turning on bit zero: 3

num: 3
num after turning on bit zero: 3

num: 4
num after turning on bit zero: 5

num: 5
num after turning on bit zero: 5

num: 6
num after turning on bit zero: 7

num: 7
num after turning on bit zero: 7

num: 8
num after turning on bit zero: 9

num: 9
num after turning on bit zero: 9

num: 10
num after turning on bit zero: 11