How to deal with php warning about using utf-8?

Question

PHP

When using php, it swears at the utf-8 constant, saying that support will stop in the next version
json_encode($array, utf-8);

Warning: Use of undefined constant utf - assumed 'utf' (this will throw an Error in a future version of PHP)

How to solve this moment? Thank you!

Answer 1

Options are passed as the second parameter. So I have the same question as php, what does the string "utf-8" do there, besides not being escaped?
Docks: php.net/manual/ru/function.json-encode.php
List of available constants: php.net/manual/ru/json.constants.php