🔵 Core C++ · Lesson 35

Command Line Arguments

What is Command Line Arguments?

Command Line Arguments
Command line arguments allow values to be passed to a program when it starts. They are received by main using argc and argv.

Level
🔵 Core C++ Features

Example File
command-line-arguments.cpp

Main Focus
Concept + syntax + practical C++ program

Why should you learn this?

It helps you write correct and readable C++ programs.
It is used repeatedly in school practicals, projects and competitive programming.
It builds the base for advanced topics such as OOP, STL and data structures.

Important Terms

Term	Meaning / Use
argc	Argc used in Command Line Arguments programming.
argv	Argv used in Command Line Arguments programming.
terminal	Terminal used in Command Line Arguments programming.
argument	Argument used in Command Line Arguments programming.
program execution	Program execution used in Command Line Arguments programming.

Syntax / Pattern

int main(int argc, char* argv[])

Example Program

#include <iostream>
using namespace std;
int main(int argc, char* argv[]){
    cout << "Arguments: " << argc;
    return 0;
}

Expected Output

Arguments: 1

Program Explanation

argc counts program name also.
argv stores arguments as character strings.

Exam Tip: In C++ practical answers, write the logic first, then the program, then expected output. For theory, always include one suitable example.

Where will you use it?

tools
automation
file processing programs

Common Mistakes

Forgetting argv[0] is program name.
Using argv index without checking argc.

Practice Tasks

Print all command-line arguments.
Create program that receives two numbers from command line.

Summary

Command Line Arguments is an important C++ topic. Learn the definition, understand the syntax, run the example program and then solve the practice tasks to make the concept strong.