.gitignore

Untitled.txt
.ipynb_checkpoints/
gist_url

element_index.ipynb

element_index.rb

def element_index(element, my_array)
  i = 0
  length = my_array.length
  while i < length
    guess = my_array[i]
    # puts [guess == element, guess]
    return i if guess == element
    i += 1
  end
  -1
end

p element_index("b", ["a", "b", "c"])
# should output 1

p element_index("hello", ["a", "b", "c"])
# should output -1

square_roots.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.0\n",
      "1.7320508075688772\n",
      "2.23606797749979\n",
      "2.6457513110645907\n",
      "3.0\n",
      "3.3166247903554\n",
      "3.605551275463989\n",
      "3.872983346207417\n",
      "4.123105625617661\n",
      "4.358898943540674\n",
      "4.58257569495584\n",
      "4.795831523312719\n",
      "5.0\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "1..25"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "(1..25).step(2).each do |n|\n",
    "  puts n ** 0.5\n",
    "end"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "*If i starts at 1 and 2 is iteratively added to it with the step method then the integers will be odd.*"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "3\n",
      "5\n",
      "7\n",
      "9\n",
      "11\n",
      "13\n",
      "15\n",
      "17\n",
      "19\n",
      "21\n",
      "23\n",
      "25\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "1..25"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "(1..25).step(2).each do |n|\n",
    "  puts n\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "collapsed": false,
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.0\n",
      "1.7320508075688772\n",
      "2.23606797749979\n",
      "2.6457513110645907\n",
      "3.0\n",
      "3.3166247903554\n",
      "3.605551275463989\n",
      "3.872983346207417\n",
      "4.123105625617661\n",
      "4.358898943540674\n",
      "4.58257569495584\n",
      "4.795831523312719\n",
      "5.0\n"
     ]
    }
   ],
   "source": [
    "i = 1\n",
    "while i <= 25\n",
    "  puts i ** 0.5\n",
    "  i += 2\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "collapsed": false,
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25]\n",
      "1.7320508075688772\n",
      "2.23606797749979\n",
      "2.6457513110645907\n",
      "3.0\n",
      "3.3166247903554\n",
      "3.605551275463989\n",
      "3.872983346207417\n",
      "4.123105625617661\n",
      "4.358898943540674\n",
      "4.58257569495584\n",
      "4.795831523312719\n",
      "5.0\n"
     ]
    }
   ],
   "source": [
    "i = 1\n",
    "odds = (1..25).step(2).to_a\n",
    "puts odds\n",
    "\n",
    "length = odds.length\n",
    "\n",
    "while i < length\n",
    "  puts odds[i] ** 0.5\n",
    "  i += 1\n",
    "end"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Ruby 2.3.0",
   "language": "ruby",
   "name": "ruby"
  },
  "language_info": {
   "file_extension": ".rb",
   "mimetype": "application/x-ruby",
   "name": "ruby",
   "version": "2.3.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}

square_roots.rb

(1..25).step(2).each do |n|
  puts n ** 0.5
end

(1..25).step(2).each do |n|
  puts n
end

i = 1
while i <= 25
  puts i ** 0.5
  i += 2
end

i = 1
odds = (1..25).step(2).to_a
puts odds

length = odds.length

while i < length
  puts odds[i] ** 0.5
  i += 1
end