C++ Syntax

C++ Syntax

Every C++ program shares the same skeleton. Once you know it, you can read almost any beginner program.

The classic full program

#include <iostream>
using namespace std;

int main() {
    cout << "Hello World!" << endl;
    return 0;
}

The building blocks

• #include <iostream> - a "header" line. It pulls in the library that gives us input and output tools.
• using namespace std; - names like cout live in a group (a namespace) named std. This line lets us write cout instead of std::cout.
• int main() - the entry point. The computer starts executing here, and this is the function it searches for.
• { } - curly braces wrap the code into a block: the lines that run together as the body of main.
• cout << "Hello World!" << endl; - an output statement that prints text to the console.
• return 0; - an ending signal meaning "all done, successfully".

Two rules to remember

• Statements end with a semicolon ;. Almost every line of C++ does work finishes with one.
• Code groups into blocks using { }. The braces tell where a list of statements begins and ends.

Why this order?

The program reads top-down: pull in tools, prepare names, open main, run statements, and say goodbye with return 0;. That rhythm is the C++ "syntax skeleton".

TL;DR

• Skeleton: header, using namespace std;, main(), a block, return 0;.
• #include loads tools; main is where execution starts.
• { } groups a block of statements.
• Statements finish with a semicolon ;.