Iterate over a fixed array

Question

I have an array (array1) that is 19 bits long initialized to 0 and another array (clave) that is 64 bits long. I want to iterate over array1 64 times while clave is also been checked. I did this:

def fase2
    j=0
    for i in 0..63
        @array1[j]=@array1[18].to_i^@array1[17].to_i^@array1[16].to_i^@array1[13].to_i^@clave[i].to_i
    j=j+1
    if j>19  
        j=0  
    end  
    end
    print @array1
    gets
end

is there a cleaner way to do this...?

Answer 1

I can think of a few improvements.

1. Call all of your variable names something more meaningful. What is in @array1? Integers? consider calling it @ints. Its good to call arrays a plural name. Same goes for j and i if possible.

2. Use (0..63).each do |i| instead of for i in 0..63. More ruby-like

3. Use spacing between operators, especially equals. j = 0 not j=0

4. Small conditionals can go on one line: j = 0 if j > 19

5. Why the magic numbers? Why are 18, 17, 16, and 13 special? Put them in an appropriately named array to start, and then use Array#reduce like so

   special_indeces = [18, 17, 16, 13]
   
   ... and then in loop ...
   
   xor = special_indeces.reduce do |val, index|
     val ^ @array1[index].to_i
   end
   

6. What is with gets at the end? What is the point of that?

Good luck, that code needs serious work.

Answer 2

This is untested, but it's more how I'd write the inner loops:

def fase2
  @clave.each do |clave|
    (0..19).each do |j|
      @array1[j] = @array1[18].to_i ^ @array1[17].to_i ^ @array1[16].to_i ^ @array1[13].to_i ^ clave.to_i
    end
  end
  print @array1
  gets
end