Introduction to nl2br PHP Function

The nl2br function in PHP is a handy tool that allows you to convert newlines (\n) into HTML line breaks (
). This function is especially useful when dealing with user-generated content, as it helps preserve the format of text input, making the content readable and well-organized on the web. In this guide, we will explore the usage of nl2br with several code examples and cover its various parameters.

Basic Usage of nl2br

The basic syntax of the nl2br function is:

<?php
echo nl2br("Hello world!\nThis is a new line.");
?>

Output:

Hello world!
This is a new line.

Using nl2br with HTML Entities

<?php
$text = "John & Doe\nJane & Roe";
echo nl2br(htmlentities($text));
?>

Output:

John & Doe
Jane & Roe

Using nl2br with Double Quotation Marks

<?php
$double_quotes_text = "Example with\n\"Double Quotes\"";
echo nl2br($double_quotes_text);
?>

Output:

Example with
"Double Quotes"

Using nl2br with Single Quotation Marks

<?php
$single_quotes_text = 'Example with\n\'Single Quotes\'';
echo nl2br($single_quotes_text);
?>

Output:

Example with
'Single Quotes'

Preserving User Input Formatting

<?php
// Assume user input is retrieved from a form
$user_input = "First Line\nSecond Line";
echo nl2br(htmlspecialchars($user_input));
?>

Output:

First Line
Second Line

Create a Simple Web Application

Let’s create a simple web application that accepts a comment and displays it with preserved formatting using nl2br.

HTML Form

<form method="post" action="display_comment.php">
    <label for="comment">Enter your comment:</label><br>
    <textarea name="comment" rows="5" cols="40"></textarea><br>
    <input type="submit" value="Submit">
</form>

PHP Script

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $comment = $_POST['comment'];
    echo '<h2>Your Comment:</h2>';
    echo nl2br(htmlspecialchars($comment));
}
?>

In this example, the user submits a comment through an HTML form. The PHP script processes the form by converting the newlines into HTML line breaks using nl2br and also ensures that HTML special characters are escaped using htmlspecialchars for security.

Using the nl2br function efficiently helps maintain the intended format of the text, providing a better user experience.

By following the above examples, you can effectively integrate nl2br into your PHP applications.

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