How does the function strtolower() help in resolving the issue of str_replace distinguishing between uppercase and lowercase letters in PHP?

When using the str_replace() function in PHP, it is important to note that it is case-sensitive. This means that if you want to replace a string regardless of its case (uppercase or lowercase), you need to ensure that the search string and the replacement string have the same case. To resolve this issue, you can use the strtolower() function to convert both the search string and the subject string to lowercase before using str_replace(). This way, the function will not distinguish between uppercase and lowercase letters.

// Example code snippet
$original_string = "Hello World";
$search_string = "hello";
$replacement_string = "Hi";

$lowercase_original = strtolower($original_string);
$lowercase_search = strtolower($search_string);

$result = str_replace($lowercase_search, $replacement_string, $lowercase_original);

echo $result; // Output: Hi World