Semicolons & Blocks in C++:

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.

For example, following are three different statements:

x = y;
y = y+1;
add(x, y);

A block is a set of logically connected statements that are surrounded by opening and closing braces. For example:

{
   cout << "Hello World"; // prints Hello World
   return 0;
}

C++ does not recognize the end of the line as a terminator. For this reason, it does not matter where on a line you put a statement. For example:

x = y;
y = y+1;
add(x, y);

is the same as

x = y; y = y+1; add(x, y);

C++ Identifiers:

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).

C++ does not allow punctuation characters such as @, $, and % within identifiers. C++ is a case-sensitive programming language. Thus, Manpower and manpower are two different identifiers in C++.

Here are some examples of acceptable identifiers:

Let us look various parts of the above program:

• The C++ language defines several headers, which contain information that is either necessary or useful to your program. For this program, the header <iostream> is needed.
• The line using namespace std; tells the compiler to use the std namespace. Namespaces are a relatively recent addition to C++.
• The next line // main() is where program execution begins. is a single-line comment available in C++. Single-line comments begin with // and stop at the end of the line.
• The line int main() is the main function where program execution begins.
• The next line cout << "This is my first C++ program."; causes the message "This is my first C++ program" to be displayed on the screen.
• The next line return 0; terminates main( )function and causes it to return the value 0 to the calling process.

Compile & Execute C++ Program:

Let's look at how to save the file, compile and run the program. Please follow the steps given below:

• Open a text editor and add the code as above.
• Save the file as: hello.cpp
• Open a command prompt and go to the directory where you saved the file.
• Type 'g++ hello.cpp ' and press enter to compile your code. If there are no errors in your code the command prompt will take you to the next line and would generate a.out executable file.
• Now, type ' a.out' to run your program.
• You will be able to see ' Hello World ' printed on the window.