What is the recommended function in PHP for replacing characters in a string?

To replace characters in a string in PHP, the recommended function is `str_replace()`. This function takes three parameters: the character(s) to search for, the character(s) to replace them with, and the string to search within. It replaces all occurrences of the specified characters in the string with the replacement characters.

// Example of using str_replace() to replace characters in a string
$string = "Hello, World!";
$new_string = str_replace(",", "!", $string);
echo $new_string; // Output: Hello! World!