Some Ruby Code Examples

gistfile1.txt

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  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<h2><center>An Example of Jupyter Notebook with Ruby 2.1.1 (iRuby)</center></h2>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<h3><center> http://jupyter.org/</center></h3>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Introduction"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "I am written in Markdown! Let's add some TeX:"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "$$ \\frac{-b \\pm \\sqrt{b^2-4ac}}{2b}.$$"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Some Ruby Code Examples "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 1. Various Ways to Square an Array of Numbers"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 4, 9, 16]\n"
     ]
    }
   ],
   "source": [
    "arr =[1,2,3,4].map(&lambda{|x|  x * x})\n",
    "puts arr\n"
   ]
  },
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   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 4, 9, 16]\n"
     ]
    }
   ],
   "source": [
    "arr2 =[1,2,3,4].map do |x|  x * x end\n",
    "puts arr2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "#<Proc:0x00000002a87b20@(pry):28>"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "tgdproc = Proc.new do |x|\n",
    "  x * x\n",
    "  end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 4, 9, 16]\n"
     ]
    }
   ],
   "source": [
    "arr3 = [1,2,3,4].map(&tgdproc)\n",
    "puts arr3"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 2. Some More Fun "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[\"Thomas\", \"Gerard\", \"Dowling\"]\n"
     ]
    }
   ],
   "source": [
    "arr3 = %w(thomas gerard dowling).map(&:capitalize)\n",
    "\n",
    "puts arr3.inspect"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "HELLO\n",
      "HELLO\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "2"
      ]
     },
     "execution_count": 12,
     "metadata": {},
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   ],
   "source": [
    " 2.times do\n",
    "    puts \"hello\".upcase\n",
    "    end  \n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "[2, 4]"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a =[1,2,3,4,5]\n",
    "a.select(&:even?)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       ":greet"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "def greet(name, informal=false)\n",
    "  if informal\n",
    "    \"hi #{name}\"\n",
    "  else\n",
    "    \"hello #{name}\"\n",
    "  end\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "\"hello tom\""
      ]
     },
     "execution_count": 20,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "greet 'tom'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "\"hi tom\""
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "greet('tom', informal=true)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "See [here](http://jupyter.org/) for a great link\n",
    "  http://jupyter.org/"
   ]
  }
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