Convert hex to decimal in Ruby

Question

I have hex numbers, and I want to convert them into decimal numbers. For example, 01 -> 1, 09 -> 9, 12 -> 18.

I tried:

01.unpack("n")

but that failed.

"01".unpack("n") # => [12337]

That is not what I want.

Do you know the correct answer?

Answer 1

String#to_i accepts an extra argument, which is the number base to use. Hexadecimal is base 16, so the following will work for you:

"01".to_i(16)

Calling the Integer function on it will also work, so long as the number has an 0x prefix:

Integer("0x01")