How can PHP developers ensure that only specific characters within a string are replaced, while others remain unaffected?

To ensure that only specific characters within a string are replaced while others remain unaffected, PHP developers can use the `str_replace()` function with an array of characters to be replaced and their corresponding replacements. This allows developers to target only the specific characters they want to change, leaving the rest of the string untouched. 

$string = "Hello, world!";
$characters_to_replace = array('o', 'l');
$replacements = array('0', '1');

$new_string = str_replace($characters_to_replace, $replacements, $string);

echo $new_string; // Output: Hell1, w0rld!

Keywords

PHP string manipulation substr_replace preg_replace regular expressions

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