Question

> [65].pack('c')
 => "A" 

In the above case 65 is stored as 1000 0010. Since c returns 8-bit unsigned char the returned value is 65 which happens to be the ASCII code for A.

I do not get the result of following two operations. Any explanations would help.

> ['A'].pack('H')
 => "\xA0" 
> ['A'].pack('h')
 => "\n" 

Answer 1

If you read the documentation you find this:

H         | String  | hex string (high nibble first)
h         | String  | hex string (low nibble first)

I don’t know why you’d need to flip nibbles, but the facility is there if you need it.

In your case A is being interpreted as A0 one way, and 0A in the other. Hex input should be provided as character pairs.