php - How to fix file_put_contents execution failure when it contains & symbol?

Question

The execution is successful like this:
<?php
$filename="test.txt";
file_put_contents($filename, "nihao");
?>

But this will fail:
<?php
$filename="test.txt";
file_put_contents($filename, "ni&hao");
?>

Please give me some advice. There is just an extra and symbol. How should I deal with this?

Answer 1

"ni&hao" Add the escape character '&' before special characters or change the double quotes to single quotes.

Answer 2

Is it possible? I have tested both methods and both are fine.

Answer 3

<?php
$filename="test.txt";
file_put_contents($filename, json_encode("ni&hao"));
?>