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 "metadata": {
  "name": "",
  "signature": "sha256:2bed6e40cd55f716f11e909c76b0c924a863909239fcbbf975814260bb7b4531"
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 15 : Pointers and Functions"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Call By Value"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 1, Page no. 5.112"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Call by value\n",
      "\n",
      "def change(x,y):\n",
      "    x=x+5\n",
      "    y=y+10\n",
      "    print \"In the function changes a&b is %d,%d\"%(x,y)\n",
      "    \n",
      "a=10\n",
      "b=20\n",
      "\n",
      "print \"\\nBefore calling the function a&b is %d,%d\"%(a,b)\n",
      "\n",
      "change(a,b)\n",
      "print \"\\nAfter calling a&b is %d,%d\"%(a,b)\n",
      "    "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "Before calling the function a&b is 10,20\n",
        "In the function changes a&b is 15,30\n",
        "\n",
        "After calling a&b is 10,20\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 2, Page no.5.113"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#program to swap(interchange) the two given variable.\n",
      "\n",
      "def swap(x,y):\n",
      "    \n",
      "    x=x+y\n",
      "    y=x-y\n",
      "    x=x-y\n",
      "    print \"In swap function x=%d, y=%d\"%(x,y)\n",
      "    return y,x\n",
      "\n",
      "a=10\n",
      "b=20\n",
      "\n",
      "print \"Before swap a=%d, b=%d\"%(a,b)\n",
      "\n",
      "\n",
      "print \"\\nAfter the calling the swap function, a=%d,b=%d\"%swap(a,b)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Before swap a=10, b=20\n",
        "In swap function x=20, y=10\n",
        "\n",
        "After the calling the swap function, a=10,b=20\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Call By Reference"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 1, Page.No.5.114"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Call By Reference\n",
      "\n",
      "def change (x,y):\n",
      "    x=x+5\n",
      "    y=y+10\n",
      "    print \"In the function change a&b is %d %d\"%(x,y)\n",
      "    return x,y\n",
      "a=10\n",
      "b=20\n",
      "print \"\\nBefore calling the function a&b is %d %d\"%(a,b)\n",
      "\n",
      "\n",
      "print \"After calling the function a&b is %d %d\"%change(a,b)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "Before calling the function a&b is 10 20\n",
        "In the function change a&b is 15 30\n",
        "After calling the function a&b is 15 30\n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 2, Page No.5.115"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to swap(intercahnge) the value of variables.\n",
      "\n",
      "a=10\n",
      "b=20\n",
      "\n",
      "print \"\\nBefore swap a=%d, b=%d\"%(swap(a,b))\n",
      "\n",
      "def swap(x,y):\n",
      "    x=x+y\n",
      "    y=x-y\n",
      "    x=x-y\n",
      "    print\"\\nIn swap function x=%d,y=%d\"%(x,y)\n",
      "    return y,x\n",
      "\n",
      "print \"\\nAfter calling swap function a=%d, b=%d\"%(b,a)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "In swap function x=20,y=10\n",
        "\n",
        "Before swap a=10, b=20\n",
        "\n",
        "After calling swap function a=20, b=10\n"
       ]
      }
     ],
     "prompt_number": 35
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 3, Page no. 5.115"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to interchange the value of variables using call by reference\n",
      "def exchange(m,n):\n",
      "    t=m\n",
      "    m=n\n",
      "    n=t\n",
      "    return n,m\n",
      "\n",
      "a,b=input(\"Enter two Numbers: \")\n",
      "\n",
      "print \"Before Exchange a=%d,b=%d\"%(a,b)\n",
      "\n",
      "\n",
      "print \"After Exchange a=%d, b=%d\"%(exchange(b,a))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter two Numbers: 10,20\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Before Exchange a=10,b=20\n",
        "After Exchange a=20, b=10\n"
       ]
      }
     ],
     "prompt_number": 3
    }
   ],
   "metadata": {}
  }
 ]
}