When we consider a C++ program, it can be defined as a collection of objects that communicate via invoking each other’s methods. Let us now briefly look into what a class, object, methods, and instant variables mean.<\/p>\n\n\n\n
Let us look at a simple code that would print the words Hello World<\/em>.<\/p>\n\n\n\n Let us look at the various parts of the above program \u2212<\/p>\n\n\n\n Let’s look at how to save the file, compile and run the program. Please follow the steps given below \u2212<\/p>\n\n\n\n Make sure that g++ is in your path and that you are running it in the directory containing file hello.cpp.<\/p>\n\n\n\n You can compile C\/C++ programs using makefile. For more details, you can check our\u00a0‘Makefile Tutorial’.<\/p>\n\n\n\n In C++, the semicolon is a statement terminator. That is, each individual statement must be ended with a semicolon. It indicates the end of one logical entity.<\/p>\n\n\n\n For example, following are three different statements \u2212<\/p>\n\n\n\n A block is a set of logically connected statements that are surrounded by opening and closing braces. For example \u2212<\/p>\n\n\n\n C++ does not recognize the end of the line as a terminator. For this reason, it does not matter where you put a statement in a line. For example \u2212<\/p>\n\n\n\n is the same as<\/p>\n\n\n\n A C++ identifier is a name used to identify a variable, function, class, module, or any other user-defined item. An identifier starts with a letter A to Z or a to z or an underscore (_) followed by zero or more letters, underscores, and digits (0 to 9).<\/p>\n\n\n\n C++ does not allow punctuation characters such as @, $, and % within identifiers. C++ is a case-sensitive programming language. Thus, Manpower<\/strong> and manpower<\/strong> are two different identifiers in C++.<\/p>\n\n\n\n Here are some examples of acceptable identifiers \u2212<\/p>\n\n\n\n The following list shows the reserved words in C++. These reserved words may not be used as constant or variable or any other identifier names.<\/p>\n\n\n\n A few characters have an alternative representation, called a trigraph sequence. A trigraph is a three-character sequence that represents a single character and the sequence always starts with two question marks.<\/p>\n\n\n\n Trigraphs are expanded anywhere they appear, including within string literals and character literals, in comments, and in preprocessor directives.<\/p>\n\n\n\n Following are most frequently used trigraph sequences \u2212<\/p>\n\n\n\n All the compilers do not support trigraphs and they are not advised to be used because of their confusing nature.<\/p>\n\n\n\n A line containing only whitespace, possibly with a comment, is known as a blank line, and C++ compiler totally ignores it.<\/p>\n\n\n\n Whitespace is the term used in C++ to describe blanks, tabs, newline characters and comments. Whitespace separates one part of a statement from another and enables the compiler to identify where one element in a statement, such as int, ends and the next element begins.<\/p>\n\n\n\n In the above statement there must be at least one whitespace character (usually a space) between int and age for the compiler to be able to distinguish them.<\/p>\n\n\n\n In the above statement 2, no whitespace characters are necessary between fruit and =, or between = and apples, although you are free to include some if you wish for readability purpose.<\/p>\n","protected":false},"excerpt":{"rendered":" When we consider a C++ program, it can be defined as a collection of objects that communicate via invoking each other’s methods. Let us now briefly look into what a class, object, methods, and instant variables mean. C++ Program Structure Let us look at a simple code that would print the words Hello World. Let us […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[250],"tags":[],"class_list":["post-3555","post","type-post","status-publish","format-standard","hentry","category-03-c"],"_links":{"self":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/3555","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/comments?post=3555"}],"version-history":[{"count":1,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/3555\/revisions"}],"predecessor-version":[{"id":3556,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/3555\/revisions\/3556"}],"wp:attachment":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/media?parent=3555"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/categories?post=3555"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/tags?post=3555"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}#include <iostream>\nusing namespace std;\n\n\/\/ main() is where program execution begins.\nint main() {\n cout << \"Hello World\"; \/\/ prints Hello World\n return 0;\n}<\/code><\/pre>\n\n\n\n\n
Compile and Execute C++ Program<\/h2>\n\n\n\n
\n
$ g++ hello.cpp\n$ .\/a.out\nHello World\n<\/code><\/pre>\n\n\n\nSemicolons and Blocks in C++<\/h2>\n\n\n\n
x = y;\ny = y + 1;\nadd(x, y);\n<\/code><\/pre>\n\n\n\n{\n cout << \"Hello World\"; \/\/ prints Hello World\n return 0;\n}\n<\/code><\/pre>\n\n\n\nx = y;\ny = y + 1;\nadd(x, y);\n<\/code><\/pre>\n\n\n\nx = y; y = y + 1; add(x, y);\n<\/code><\/pre>\n\n\n\nC++ Identifiers<\/h2>\n\n\n\n
mohd zara abc move_name a_123\nmyname50 _temp j a23b9 retVal\n<\/code><\/pre>\n\n\n\nC++ Keywords<\/h2>\n\n\n\n
asm<\/td> else<\/td> new<\/td> this<\/td><\/tr> auto<\/td> enum<\/td> operator<\/td> throw<\/td><\/tr> bool<\/td> explicit<\/td> private<\/td> true<\/td><\/tr> break<\/td> export<\/td> protected<\/td> try<\/td><\/tr> case<\/td> extern<\/td> public<\/td> typedef<\/td><\/tr> catch<\/td> false<\/td> register<\/td> typeid<\/td><\/tr> char<\/td> float<\/td> reinterpret_cast<\/td> typename<\/td><\/tr> class<\/td> for<\/td> return<\/td> union<\/td><\/tr> const<\/td> friend<\/td> short<\/td> unsigned<\/td><\/tr> const_cast<\/td> goto<\/td> signed<\/td> using<\/td><\/tr> continue<\/td> if<\/td> sizeof<\/td> virtual<\/td><\/tr> default<\/td> inline<\/td> static<\/td> void<\/td><\/tr> delete<\/td> int<\/td> static_cast<\/td> volatile<\/td><\/tr> do<\/td> long<\/td> struct<\/td> wchar_t<\/td><\/tr> double<\/td> mutable<\/td> switch<\/td> while<\/td><\/tr> dynamic_cast<\/td> namespace<\/td> template<\/td> <\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Trigraphs<\/h2>\n\n\n\n
Trigraph<\/th> Replacement<\/th><\/tr> ??=<\/td> #<\/td><\/tr> ??\/<\/td> \\<\/td><\/tr> ??’<\/td> ^<\/td><\/tr> ??(<\/td> [<\/td><\/tr> ??)<\/td> ]<\/td><\/tr> ??!<\/td> |<\/td><\/tr> ??<<\/td> {<\/td><\/tr> ??><\/td> }<\/td><\/tr> ??-<\/td> ~<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Whitespace in C++<\/h2>\n\n\n\n
Statement 1<\/h3>\n\n\n\n
int age;\n<\/code><\/pre>\n\n\n\nStatement 2<\/h3>\n\n\n\n
fruit = apples + oranges; \/\/ Get the total fruit\n<\/code><\/pre>\n\n\n\n