C++ - Output & Printing

Overview

Estimated time: 20–30 minutes

Print text and numbers using std::cout. Learn newlines, basic manipulators, and formatting tips.

Learning Objectives

• Use std::cout with string and numeric values.
• Print new lines with '\n' and std::endl.
• Use iostream manipulators for simple formatting.

Prerequisites

• C++ - First Program

Print text and numbers

#include <iostream>
int main(){
  std::cout << "Hello, ";
  std::cout << "world" << "!\n";
  std::cout << 42 << '\n';
}

Newlines

std::cout << "line 1\nline 2\n";
std::cout << "line 3" << std::endl; // flushes the stream

Basic manipulators

#include <iomanip>
std::cout << std::setw(5) << 7 << "\n";   // pad width 5
std::cout << std::hex << 255 << "\n";    // hex output

Common Pitfalls

• Using std::endl for every newline can cause unnecessary flushing; prefer '\n'.

Checks for Understanding

1. How do you print a newline without flushing?

Exercises

1. Print a table with two columns (left label, right value) using setw.