{
"metadata": {
"name": "",
"signature": "sha256:ebda2195f5f56b03f9c5aecb268e628cfb74a1a1fa1ea18ae277cc3f964d54bd"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 6: Pointing to data"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.1, Page No.98"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"num=100\n",
"sum=0.0123456789\n",
"text=\"C++ Fun\"\n",
"print \"Integer variable starts at\",hex(id(num))\n",
"print \"Double variable starts at\",hex(id(sum))\n",
"print \"String variable starts at\",hex(id(text))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Integer variable starts at 0x126eb04\n",
"Double variable starts at 0x279b490\n",
"String variable starts at 0x2b7a160\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.2, Page No.100"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"a=8\n",
"b=16\n",
"aPtr=id(a)\n",
"bPtr=id(b)\n",
"print \"Address of pointers...\"\n",
"print \"aPtr:\",hex(id(aPtr))\n",
"print \"bPtr:\",hex(id(bPtr))\n",
"print \"Values in pointers...\"\n",
"print \"aPtr:\",hex(aPtr)\n",
"print \"bPtr:\",hex(bPtr)\n",
"#As python does not support pointers values can't be displayed using * symbol"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Address of pointers...\n",
"aPtr: 0x2808ac8\n",
"bPtr: 0x2808b1c\n",
"Values in pointers...\n",
"aPtr: 0x126e794\n",
"bPtr: 0x126e734\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3, Page No.102"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"nums={1,2,3,4,5,6,7,8,9,10}\n",
"ptr=id(nums)\n",
"#As python does not support concept of pointers we can not use pointer arithmetic to print numbers"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.4, Page No.104"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"num=5\n",
"def writeOutput(value):\n",
" print \"Current Value: \",value\n",
"def computeTriple(value):\n",
" global num\n",
" num=num*3\n",
"\n",
"\n",
"writeOutput(num)\n",
"num=num+15\n",
"writeOutput(num)\n",
"computeTriple(num)\n",
"writeOutput(num)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current Value: 5\n",
"Current Value: 20\n",
"Current Value: 60\n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.5, Page No.106"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"letters=['C','+','+',' ','F','u','n','\\0']\n",
"text=\"C++ Fun\"\n",
"term=\"Element\"\n",
"lang=\"C++\"\n",
"ap1=[\"Great \",\"Program \",\"Code \"]\n",
"ap2=[lang,\"is \",\"Fun\"]\n",
"ap3=[ap2[0],ap2[1],ap1[0]]\n",
"ap4=[ap1[2],ap2[1],ap2[2]]\n",
"print \"\".join(letters)\n",
"print text\n",
"for i in range(0,3):\n",
" print term,i,\" \",\n",
" print ap1[i],\" \",\n",
" print ap2[i],\" \",\n",
" print ap3[i],\" \",\n",
" print ap4[i],\" \""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"C++ Fun\u0000\n",
"C++ Fun\n",
"Element 0 Great C++ C++ Code \n",
"Element 1 Program is is is \n",
"Element 2 Code Fun Great Fun \n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.6, Page No.108"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"num=0\n",
"rNum=400\n",
"num=rNum\n",
"print \"Value direct\",num\n",
"print \"Value via reference \",rNum\n",
"\n",
"print \"Address direct\",hex(id(num))\n",
"print \"Address via reference\",hex(id(rNum))\n",
"\n",
"rNum=rNum*2\n",
"num=rNum\n",
"\n",
"print \"Value direct\",num\n",
"print \"Value via reference \",rNum\n",
"\n",
"#as python does not support pointers"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Value direct 400\n",
"Value via reference 400\n",
"Address direct 0x27cd294\n",
"Address via reference 0x27cd294\n",
"Value direct 800\n",
"Value via reference 800\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.7, Page No. 110"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"def writeOutput(value):\n",
" print \"Current Value: \",value\n",
"\n",
"def computeTriple(value):\n",
" value=value*3\n",
" print \"Current Value: \",value\n",
" \n",
"num=5\n",
"ref=num\n",
"writeOutput(num)\n",
"num=num+15\n",
"writeOutput(num)\n",
"computeTriple(num)\n",
"\n",
"#as python does not support pointers I dont have used pointer in this program"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current Value: 5\n",
"Current Value: 20\n",
"Current Value: 60\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.8, Page No.113"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"def add(a,b):\n",
" total=a+b\n",
" print \"total:\",total\n",
"\n",
"num=100\n",
"sum=500\n",
"rNum=num\n",
"ptr=num\n",
"print \"Reference:\",rNum\n",
"print \"Pointer:\",ptr\n",
"ptr=sum\n",
"print \"Pointer now:\",ptr\n",
"add(rNum,ptr)\n",
"\n",
"\n",
"#as python does not support pointers I dont have used pointer in this progaram"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Reference: 100\n",
"Pointer: 100\n",
"Pointer now: 500\n",
"total: 600\n"
]
}
],
"prompt_number": 10
}
],
"metadata": {}
}
]
}