What do two left-angle brackets “<<” mean in C#?

Question

Basically the questions in the title. I\'m looking at the MVC 2 source code:

[Flags]
public enum HttpVerbs {
    Get = 1 << 0,
    Post = 1 << 1,         


        

Answer 1

It is Bitwise shift left it works by shifting digits of binary equivalent of number by the given (right hand side) numbers.

so:

temp = 14 << 2

binary equivalent of 14 is 00001110 shifting it 2 times means pushing zero from right hand side and shifting each digit to left side which make it 00111000 equals to 56.

In your example:

i < (1 << list.Count)

• 0000000001 = 1 if list.Count = 0 result is 0000000001 = 1
• 0000000001 = 1 if list.Count = 1 result is 0000000010 = 2
• 0000000001 = 1 if list.Count = 2 result is 0000000100 = 4
• 0000000001 = 1 if list.Count = 3 result is 0000001000 = 8

and so on. In general it is equal 2 ^ list.Count (2 raised to the power of list.Count)