What are some potential pitfalls or issues that may arise when using str_replace in PHP?

One potential issue when using str_replace in PHP is that it is case-sensitive by default, meaning it will only replace exact matches. To solve this, you can use the str_ireplace function instead, which is case-insensitive.

// Case-insensitive replacement using str_ireplace
$string = "Hello World";
$new_string = str_ireplace("hello", "Hi", $string);
echo $new_string; // Output: Hi World