Syntax in C++

The syntax of C++ defines how statements and expressions should be structured in order to create valid programs. It includes rules for writing declarations, expressions, control structures, functions, and more.

Basic Structure of a C++ Program

A C++ program typically consists of preprocessor directives, global declarations, and the main function. The main function is the entry point of the program where the execution starts.

#include<iostream>
int main() {
    // Output a message to the console
    std::cout << "Enter your name: ";
    // Input a string from the user
    std::string name;
    std::cin >> name;
    // Output a personalized greeting
    std::cout << "Hello, " << name << "! Welcome to C++!" << std::endl;
    return 0;
}

• #include <iostream>: This line includes the iostream library, which provides input and output functionalities, such as cout and cin.
• int main(): This is the main function of the program, which serves as the entry point. It has a return type of int and doesn't take any parameters.
• std::cout << "Enter your name: ";: The std::cout statement is used to output (print) text to the console. In this case, it displays the message "Enter your name: ".
• std::cin >> name;: The std::cin statement is used to read input from the user. It takes the input and stores it in the variable name, which is of type std::string (a string data type in C++).
• std::cout << "Hello, " << name << "! Welcome to C++!" << std::endl;: This line uses std::cout to output a personalized greeting to the console. It combines the string literals ("Hello, " and "! Welcome to C++!") with the user's input stored in the name variable using the << operator.
• return 0;: This statement indicates the end of the main function and returns a value of 0 to the operating system, indicating successful program execution.

In this example, the program prompts the user to enter their name, reads the input, and then outputs a personalized greeting message. The cout object is used for output, allowing you to display text and values on the console. The cin object is used for input, allowing you to read user input from the console.