Proper way to escape json data in PHP without using JS comment hack

Question

Consider the code below to send a json string to js from php,

<?php
    $str = "<!--<script>"; // This is from user input
?>

<script>
   var json_str = <?= json_encode($str) ?>;
</script>

The string will break the HTML, and the way to solve it is via something like the old school comment hack, eg

<script>
<!--
   var json_str = <?= json_encode($str) ?>;
//-->
</script>

Are there any alternative?

Answer 1

您可以使用标志JSON_HEX_TAG ，以便<和>被编码为\<和\> 。

json_encode($str, JSON_HEX_TAG)