IT212 Data Structure

Binary Integers

• Boolean - 1bit,
• Nibble - 4bits,
• Byte - 8 bits,
• Word - 16 bit,
• Long Word - 32 or 64 bit
• Big Integer - growing memory size

a = 9**10
puts a
(8*a.size).downto(0) do |n|
      print a[n]
end
puts

puts "|Integer | Bytes | Float render|"
puts "|:------:|:-------:|:--------:|"
40.times do |i|
   a = 10**(i*10)
   puts "|10^#{i*10}| #{a.size} bytes| #{a.to_f}|"
end

Float Max : 1.7976931348623157e+308 Float Min : 2.2250738585072014e-308

Float Mantissa - 53 bits

Real numbers:

• float:

sum = 0
10_000.times do
  sum = sum + 0.0001
end
print sum #=> 0.9999999999999062

• BigDecimal:

require 'bigdecimal'

sum = BigDecimal("0")
10_000.times do
  sum = sum + BigDecimal("0.0001")
end
print sum #=> 0.1E1

Key methods

• Bit operators

  • ~ Invert bits

  • | : OR

  • & : AND

  • ^ : XOR

  • << : left shift

  • >> : right shift

  • <=> : comparison -1 , 0 , 1 - less, equal, greater

• Changing Data types

  • .to_i : to integer
  • .to_f : to float
  • .to_r : to rational number
  • .to_s : to string

• float to integer

  • .floor() return to the previous integer

  • .round() move to the next integer if decimal >= 0.5

  • .ceiling() go to the next integer