Introduction (and some facts about C++)

Below shown is a basic C++ program to print 'Hello World'

Let's understand the syntax by observing each line of code.

#include <iostream> using namespace std; int main() { cout << "Hello World!"; return 0; }

Line 1: "#include " is a header file library that lets us work with input and output objects, such as cout (used in line 5). Header files add functionality to C++ programs.

Line 2: "using namespace std" means that we can use names for objects and variables from the standard library.

Note:- Don't worry if you don't understand how #include and using namespace std works. Just think of it as something that (almost) always appears in your program.

Line 3: A blank line. C++ ignores white space. But we use it to make the code more readable.

Line 4: Another thing that always appear in a C++ program, is 'int main()'. This is called a function. Any code inside its curly brackets '{}' will be executed.

Line 5: 'cout' (pronounced "see-out") is an object used together with the insertion operator (<<) to output/print text. In our example it will output "Hello World".

Note: Every C++ statement ends with a semicolon ';'.

Note: The body of 'int main()' could also been written as:
"int main () { cout << "Hello World! "; return 0; }"

Remember: The compiler ignores white spaces. However, multiple lines makes the code more readable.

Line 6: 'return 0' ends the main function.

Line 7: Do not forget to add the closing curly bracket '}' to actually end the main function.