Why Are My Newline Characters Not Converting to HTML Break Tags?

Preserving Newline Characters with HTML

In an attempt to convert newlines or "rn" characters into HTML break tags ("
"), a user encountered difficulties despite employing various methods.

Method Exploration

1. preg_replace():

   <code class="php">$description = preg_replace('/\r?\n|\r/', '<br/>', $description);</code>

2. str_replace():

   <code class="php">$description = str_replace(array("\r\n", "\r", "\n"), '<br/>', $description);</code>

3. nl2br():

   <code class="php">$description = nl2br($description);</code>

Unexpected Results

Despite these plausible methods, the newlines remained in the text. The reason lay in the unexpected presence of double newlines ("rr"). While this should not hinder the replacement, it warranted further investigation.

nl2br() Function

It is important to note the existence of the nl2br() function, which explicitly inserts "
" tags before new line characters.

<code class="php"><?php
// Won't work
$desc = 'Line one\nline two';
// Should work
$desc2 = "Line one\nline two";

echo nl2br($desc);
echo '<br/>';
echo nl2br($desc2);
?></code>

Double-Quoted Text

Furthermore, special attention should be paid to the use of double quotation marks when assigning the text to the variable.

<code class="php">$description = "Line one\nline two"; // Correct
$description = 'Line one\nline two'; // Incorrect</code>

This is because single quotes do not 'expand' escape sequences, such as 'n,' which is crucial for interpreting new line characters.

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