Pointers Part 1: The Basics



So you're eager to learn about pointers but unfortunately you got stuck because they seemed to you terrible in nature? That's not true I know, but many of the people get confused when they arrive at the topic of pointers. Well pointers are the most important tools in C programming and are the one that can make you fly (unless you don't know how to ride over them). In this article we're going to learn basics of pointers.
Pointers are the varaibles that store addresses of other variables. Easy ain't it?
So lets start with the decleration of a pointer, pointer is decreleared as:
data_type *var_name;
e,g
int *pt;
well the astrisk(*) before the variable name is the thing that makes variable a pointer. So far so good now what?
Now lets say we want to store address of a variable in our pointer variable that seems pretty complex..!
Let's do it:
int number = 100;
int *pt = #
Is it really complex..?
what we are doing here is that we are first declaring and initializing a integer variable (number) with value of 100 and then we declare and initialize a pointer variable (pt) with the address of number variable. Now pt (pointer variable) contains the address of number (integer varaible). So what? Now we can use this pointer variable to change the value of number variable. Is this some kind of Magic? Maybe. Lets' do it:
*pt = 200;
what we have done here is that we De-referencing the pt variable with the asterisk (*) and then assigned it the value of 200 now the number variable contains 200. Isn't it a magic? De-referencing is used for accessing the value of the variable towards which our pointer is pointing simple. So lets write a full program of what we have learned so far.
/*Pointer Basics: Creating and Using Pointers*/
#include<stdio.h>
int main(void){
  int number = 100;
  int *pt = &number;
  printf("Value of 'number' is: %d", number);
  printf("Address of 'number' is: %p", pt);
  *pt = 200;
  printf("New value of 'number' is: %d", number);
  return 0;
}
What this whole program did was it created a integer variable and a pointer to integer variable and then printed out the value and address of the 'number' variable and after that we De-referenced the pointer variable so that we can access the value to which our pointer variable is pointing and changed the old 100 value with new 200 value and at last we printed that out. Easy isn't it?
But do you know that you can get the address of a variable even by using ampersand (&) operator? Lemme show you how. I'll declare and initialize a variable 'var' and then print it to screen using ampersand (&) operator:
int var = 10;
printf("Address of 'var' is %p\n", &var);
the last statement here will print out the address of 'var' not value so that means it is equal to this statement:
int *pt = &var;
printf("Address of 'var' is %p\n", pt);
here we first assigned the address of 'var' to pointer variable 'pt' and then printed out the address of 'var' using the pointer variable (pt).
So lets write another program that will wrap up this part of 'Pointer Basics':
/*Pointer Basics Part 1: Program 2*/
#include<stdio.h>
int main(void){
   int var = 10;
   int *pt = &var;
   printf("The Value of 'var' is: %d\n", var);
   printf("De-referencing: *pt = %d\n", *pt);
   printf("Ampersand: The Address of 'var' is %p\n",  &var);
   printf("pt = %p\n", pt);
   return 0;
}
So that's the end of first part watch out for the next part in which we'll tighten our grip on pointers and get ready for some Advanced '*po(inter)-fo'.
Related news
  1. Hack Tool Apk
  2. Hacker Tools Mac
  3. Pentest Tools Review
  4. Hacking Tools Download
  5. Pentest Tools Tcp Port Scanner
  6. How To Hack
  7. Best Pentesting Tools 2018
  8. Tools Used For Hacking
  9. Hacking Tools 2019
  10. Pentest Tools Github
  11. Hacking Tools Online
  12. Hacking Tools Download
  13. Best Hacking Tools 2019
  14. Usb Pentest Tools
  15. Hackers Toolbox
  16. Hack Tools For Mac
  17. Pentest Tools Website Vulnerability
  18. Hack Tools
  19. Pentest Tools Windows
  20. Github Hacking Tools
  21. Hacking Apps
  22. Blackhat Hacker Tools
  23. Hacker Tools 2019
  24. Hacker Tools Github
  25. Hacking Tools Kit
  26. How To Hack
  27. Pentest Tools Find Subdomains
  28. Blackhat Hacker Tools
  29. Tools For Hacker
  30. Hack Tool Apk
  31. Hacker Tools Apk Download
  32. Hacking Tools For Pc
  33. Hacker Tools 2020
  34. Hacker Tools Hardware
  35. Pentest Tools Free
  36. Hacker Tools Hardware
  37. Hacking Tools Windows
  38. Pentest Tools Framework
  39. Pentest Automation Tools
  40. Best Hacking Tools 2019
  41. Hacker Tools List
  42. Pentest Tools Nmap
  43. Hack Tools Mac
  44. How To Install Pentest Tools In Ubuntu
  45. Android Hack Tools Github
  46. Hacker Tools For Pc
  47. Free Pentest Tools For Windows
  48. Hack Tools
  49. Pentest Tools Github
  50. Hacking Tools Software
  51. Pentest Tools For Android
  52. Pentest Tools Find Subdomains
  53. Pentest Tools Github
  54. Beginner Hacker Tools
  55. Hacker
  56. Pentest Tools Windows
  57. Usb Pentest Tools
  58. Hacking Tools For Mac
  59. What Are Hacking Tools
  60. Pentest Tools
  61. Hacker Tools For Ios
  62. Hack Tools Online
  63. Hacking Tools For Windows Free Download
  64. Hack Tools Online
  65. Hack Tools
  66. Hacking Tools Kit
  67. Hackers Toolbox
  68. How To Hack
  69. Pentest Tools Website
  70. Pentest Tools
  71. Hack Tools
  72. Ethical Hacker Tools
  73. Hacking Tools Windows 10
  74. How To Hack
  75. Hacker Tools
  76. Kik Hack Tools
  77. Hack Tools For Mac
  78. Hacking Tools Download
  79. Blackhat Hacker Tools
  80. Hacking Tools Mac
  81. Hacking Tools Pc
  82. Pentest Tools Find Subdomains
  83. Blackhat Hacker Tools
  84. Hack App
  85. Hack Tools For Pc
  86. Hacker Tools Apk
  87. Pentest Tools Port Scanner
  88. How To Hack
  89. Hack Apps
  90. Hack Tools
  91. Hack Tools For Windows
  92. Hacking Apps
  93. Growth Hacker Tools
  94. Pentest Tools Nmap
  95. Hack Tools For Pc
  96. Hacking Tools For Mac
  97. Hacking Tools Windows 10
  98. Hacking Tools Hardware
  99. Hacker Tools 2020
  100. Pentest Tools Github
  101. Hack Tools Mac
  102. Hack Tools For Pc
  103. Hack Website Online Tool
  104. Hack Tool Apk No Root
  105. Pentest Tools Bluekeep
  106. Pentest Tools Website Vulnerability
  107. Hacking Tools Software
  108. Hack Tools Pc
  109. Install Pentest Tools Ubuntu
  110. Pentest Tools Alternative
  111. Best Pentesting Tools 2018
  112. World No 1 Hacker Software
  113. Black Hat Hacker Tools
  114. Tools For Hacker
  115. Hacking Tools Windows 10
  116. Hacking Tools For Kali Linux
  117. Hacking Tools For Mac
  118. Hack Tools
  119. Hack Tools For Games
  120. Best Hacking Tools 2019
  121. Pentest Tools Review
  122. Hack Website Online Tool
  123. Hacker Tools

No comments:

Post a Comment

Blog Archive