{"id":211,"date":"2020-08-31T10:04:54","date_gmt":"2020-08-31T10:04:54","guid":{"rendered":"https:\/\/www.kindsonthegenius.com\/cplusplus\/?p=211"},"modified":"2020-08-31T10:04:54","modified_gmt":"2020-08-31T10:04:54","slug":"c-pointers","status":"publish","type":"post","link":"https:\/\/www.kindsonthegenius.com\/cplusplus\/c-pointers\/","title":{"rendered":"C++ Pointers"},"content":{"rendered":"

In this lesson, we would learn about C++ pointers. This is one of the few topics that is distinguishes C++ from many other programming languages. So, it’s important you understand it.<\/p>\n

    \n
  1. Overview of C++ Pointers<\/a><\/li>\n
  2. Creating Pointers<\/a><\/li>\n
  3. Using Pointers in C++<\/a><\/li>\n
  4. Some Pointer Concepts<\/a><\/li>\n<\/ol>\n

     <\/p>\n

    1. Overview of C++ Pointers<\/strong><\/h4>\n

    Pointers in C++ are variables that store memory address of other variables. So if you have a variable x, then to get its memory address, you use &x. The code below displays address of three variables<\/p>\n

    \/\/ Printing memory addresses of variables<\/span>\r\nint<\/span> main<\/span> () {\r\n    \/\/ declare some variables<\/span>\r\n    int<\/span> x =<\/span> 67<\/span>;\r\n    string name =<\/span> \"Kindson\"<\/span>;\r\n    double<\/span> y =<\/span> 54.32<\/span>;\r\n\r\n    \/\/ print address of x<\/span>\r\n    cout <<<\/span> \"Address of x: \"<\/span><<<\/span> &<\/span>x <<<\/span> endl;\r\n\r\n    \/\/ print address of name<\/span>\r\n    cout <<<\/span> \"Address of name: \"<\/span> <<<\/span> &<\/span>name <<<\/span> endl;\r\n\r\n    \/\/ print address of y<\/span>\r\n    cout <<<\/span> \"Address of y: \"<\/span> <<<\/span> &<\/span>y <<<\/span> endl;\r\n\r\n    return<\/span> 0<\/span>;\r\n}\r\n<\/pre>\n
    The output of the program is:<\/p>\n
    Address of x: 0x62fe08\r\nAddress of name: 0x62fde0\r\nAddress of y: 0x62fdd8\r\n<\/pre>\n
    As you can see, the addressed are shown in hexadecimal (begins with 0x)<\/p>\n
     <\/p>\n
    2. Creating Pointers<\/strong><\/h4>\n
    Similar to normal variables, you also need to declare a pointer before you can use it. However, pointer names are preceded by an asterisk(*). For example<\/p>\n
    int<\/span> *<\/span>myPointer; \/\/pointer to int<\/span>\r\n\r\nint<\/span>*<\/span> myPointer; \/\/pointer to int<\/span>\r\n\r\nint<\/span>*<\/span> myPointer, myVar; \/\/a pointer and an int<\/span>\r\n<\/pre>\n
    The three lines above are all valid ways to declare a pointer. The first and second lines declares a pointer myPointer<\/em> which is a pointer to an int variable. Third line declares a pointer myPointer<\/em> and a normal variable myVar<\/em>.<\/p>\n
     <\/p>\n
    3. Using Pointers in C++<\/strong><\/h4>\n
    Let’s now create a pointer and assign the address of a variable to it.<\/p>\n
    \/\/ Working with point<\/span>\r\nint<\/span> main<\/span> () {\r\n    \/\/ declare a variables, x<\/span>\r\n\tint<\/span> x =<\/span> 34<\/span>;\r\n\r\n\t\/\/ declare a pointer px<\/span>\r\n\tint<\/span> *<\/span>px;\r\n\r\n\t\/\/ assign the pointer a value<\/span>\r\n\tpx =<\/span> &<\/span>x;\r\n\r\n\t\/\/ display the pointer value<\/span>\r\n\tcout<<<\/span>\"Variable x \"<\/span> <<<\/span> x <<<\/span> \" is stored at \"<\/span> <<<\/span> px;\r\n\r\n    return<\/span> 0<\/span>;\r\n}\r\n<\/pre>\n
    The output is:<\/p>\n
    Variable x 34 is stored at 0x62fe14\r\n<\/pre>\n
    Moreover, if you have a pointer and you want to know what value is stored there, you just also use *. The code below would get the value stored in px.<\/p>\n
    cout<<<\/span>\"Value stored in \"<\/span> <<<\/span> px <<<\/span> \" is \"<\/span> <<<\/span> *<\/span>px;\r\n<\/pre>\n
     <\/p>\n
    4. Some Pointer Concepts<\/strong><\/h4>\n
    There are a few concepts on pointers I would like to mention here finally.<\/p>\n\n\n\n\n\n\n\n\n\n\n
    SN<\/th>\nConcept & Description<\/th>\n<\/tr>\n
    1<\/td>\nNull Pointers<\/strong>A null pointer is is a constant with a value of zero defined in several standard libraries.<\/td>\n<\/tr>\n
    2<\/td>\nPointer Arithmetic<\/strong>Also, you can also perform arithmetic operations with pointers. The four arithmetic operators that you can use on pointers are: ++, –, +, –<\/td>\n<\/tr>\n
    3<\/td>\nPointers vs Arrays<\/strong>There is a relationship between pointers and arrays. We’ll explore this in later lessons<\/td>\n<\/tr>\n
    4<\/td>\nArray Pointers<\/strong>You can define arrays to hold a number of pointers.<\/td>\n<\/tr>\n
    5<\/td>\nPointer to Pointer<\/strong>C++ allows you to have pointer holding the memory address of another pointer.<\/td>\n<\/tr>\n
    6<\/td>\nPassing Pointers to Functions<\/strong>Passing arguments by reference or by address both allow for the passed argument to be modified in the calling function by the called function.<\/td>\n<\/tr>\n
    7<\/td>\nReturning Pointer from Functions<\/strong>You can also allows to function to return a pointer to local variable, static variable as well as\u00a0 dynamically allocated memory.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    <\/div>\n
    I recommend you ensure to understand clearly the concept of pointers in C++. Get more support from my YouTube Channel, Kindson The Tech Pro.<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"
    In this lesson, we would learn about C++ pointers. This is one of the few topics that is distinguishes C++ from many other programming languages. … <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[32],"class_list":["post-211","post","type-post","status-publish","format-standard","hentry","category-c-tutorials","tag-pointers"],"_links":{"self":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/comments?post=211"}],"version-history":[{"count":1,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/211\/revisions"}],"predecessor-version":[{"id":212,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/211\/revisions\/212"}],"wp:attachment":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/media?parent=211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/categories?post=211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/tags?post=211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}