C++ Manipulators Tutorial: endl, setw, and Output Formatting

Learn C++ manipulators like endl and setw with beginner-friendly examples. Understand how to format output, align columns, and improve console display in C++ programs.

C++ manipulators are special tools used with cout to control or format the output.

In this lesson, we will learn two commonly used manipulators:

1. endl – moves the cursor to the next line.
2. setw – sets the width of the output field.

1. Manipulator: endl

What is endl?

endl is used with cout to:

• Move the cursor to the next line.
• Complete the current output line.
• Make the output easier to read.

Syntax

cout << "Text" << endl;

Example

Question: Write a C++ program that prints two lines of text using the manipulator endl.

Program

#include <iostream>
using namespace std;

int main() {

    cout << "Hello, C++ beginners!" << endl;
    cout << "This line is printed using endl.";

    return 0;
}

Output

Hello, C++ beginners!
This line is printed using endl.

Understand the Code

cout << "Hello, C++ beginners!" << endl;

• cout displays the text.
• "Hello, C++ beginners!" is the text to display.
• endl moves the cursor to the next line.

Therefore, the second cout statement starts printing from a new line.

Remember

endl is mainly used to move output to the next line.

2. Manipulator: setw

What is setw?

setw means set width.

It is used to set the minimum width of the output field. It is especially useful when displaying data in columns or tables.

Important

setw is available in the <iomanip> library.

Therefore, we need to include:

#include <iomanip>

Syntax

setw(number)

For example:

cout << setw(10) << 25;

This gives the output field a width of 10 characters.

Example: Using setw to Create a Table

Question: Write a C++ program that prints a simple table of numbers using setw to align the output in columns.

Program

#include <iostream>
#include <iomanip>

using namespace std;

int main() {

    cout << setw(10) << "Number"
         << setw(10) << "Square" << endl;

    cout << setw(10) << 2
         << setw(10) << 4 << endl;

    cout << setw(10) << 5
         << setw(10) << 25 << endl;

    cout << setw(10) << 10
         << setw(10) << 100 << endl;

    return 0;
}

Output

    Number    Square
         2         4
         5        25
        10       100

Understand the Code

Consider this statement:

cout << setw(10) << 2
     << setw(10) << 4 << endl;

• setw(10) gives the first value a field width of 10 characters.
• 2 is displayed within that field.
• The second setw(10) gives the next value another field width of 10 characters.
• 4 is displayed within the second field.
• endl moves the cursor to the next line.

This helps us display values in aligned columns.

Important Point About setw

setw() applies only to the next output item.

For example:

cout << setw(10) << 25 << 50;

Here, setw(10) applies to 25 only. It does not automatically apply to 50.

If we want both values to have a width of 10, we write:

cout << setw(10) << 25
     << setw(10) << 50;

Quick Comparison

Remember

• endl → New line
• setw() → Set output width
• setw() requires <iomanip>
• setw() affects only the next output item

Practice Questions

Practice 1 – endl

Write a C++ program that displays your:

• Name
• Department
• Semester

Use endl to print each item on a separate line.

Practice 2 – setw

Write a C++ program to display the following table using setw(10):

Number    Cube
2         8
3         27
4         64
5         125

Practice 3 – Both Manipulators

Write a C++ program that uses both endl and setw() to display a simple student information table containing:

• Roll No.
• Name
• Marks