binary.md

Binary

Write a program that will convert a binary number, represented as a string (i.e. "101010"), to it's decimal equivalent using first principles (i.e. no, you may not use built-in ruby libraries or gems to accomplish the conversion).

The program should consider strings specifying an invalid binary as the value 0.

This is how computers work:

# "1011001"
  1     0     1     1     0     0     1
2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0
 64 +   0 +  16 +   8 +   0 +   0 +   1 = 89

If you want to write extra tests and/or check your answers, feel free to use irb:

irb(main):001:0> 0b1011001
=> 89
irb(main):002:0> 0b1101
=> 13
irb(main):003:0> 0b110110110110101
=> 28085

Tests are provided, delete one skip at a time.

Source

All of Computer Science