Prerequisition

• I am using Arch based Linux
• gcc and clang installed via pacman

Input Output

🚴 PRACTICE | simple cli app

copy this code to file main.cpp

#include <iostream>

int main() {
  // Getting stdin (standard input):
  std::cout << "Enter a line of text: " << std::endl;
  return 0;
}

run with gcc

g++ -Wall -std=c++20 main.cpp -o test

or run with clang

clang++ -Wall -std=c++20 main.cpp -o test

run the output file ./test

🚴 PRACTICE | using namespace

try this code:

#include <iostream>
#include <sstream>
#include <string>
using namespace std;

int main() {
    string input;
    getline(cin, input);

    stringstream ss(input);
    int number;
    int sum = 0;

    while (ss >> number) {
        sum += number;
    }

    cout << sum << endl;

    return 0;
}

Explanation

• iostream: For input and output (std::cin, std::cout).
• sstream: For string streams (std::stringstream).
• string: For string manipulation (std::string).
• std::string input; declares a string variable to store the input.
• std::cout << "Enter numbers separated by spaces: "; prompts the user for input.
• std::getline(std::cin, input); reads the entire line of input, including spaces.
• std::stringstream ss(input); creates a string stream from the input string. This allows us to extract numbers from the string.
• int number; declares an integer variable to store each number.
• int sum = 0; initializes the sum to 0.
• while (ss >> number): This loop reads numbers from the string stream until there are no more numbers.
• ss >> number extracts the next number from the string stream and stores it in the number variable.

references:

• cppreference.com