What potential pitfalls should be considered when manipulating strings in PHP, such as removing characters like slashes?

When manipulating strings in PHP, one potential pitfall to consider is unintentionally removing necessary characters, such as slashes. To avoid this issue, it is important to carefully assess which characters need to be removed and which need to be retained. One solution is to use PHP's built-in functions like `str_replace()` or `preg_replace()` with caution to ensure that only the intended characters are removed.

// Example of removing slashes from a string using str_replace()
$string = "This/is/a/test/string";
$cleaned_string = str_replace("/", "", $string);
echo $cleaned_string;