What is the recommended approach in PHP to remove multiple occurrences of a specific character in a string efficiently?

To efficiently remove multiple occurrences of a specific character in a string in PHP, one recommended approach is to use the `str_replace()` function. This function allows you to specify the character you want to remove and replace it with an empty string. By using this function, you can easily remove all instances of the specified character in the string.

// Original string
$string = "Hello, World! This is a test string.";

// Character to remove
$char_to_remove = 'o';

// Remove all occurrences of the specified character
$new_string = str_replace($char_to_remove, '', $string);

// Output the new string
echo $new_string;