使用直接输出将JSON从PHP传递给Javascript

Question

Without using AJAX, how to correctly write a JSON string to JS from PHP. Example below, some case will break this code. I'm trying to find a perfect way to display json correctly, for both case "a" and "b"

Write the output JS to browser console, you'll see it breaks.

<?php
$var = array(
        'nokey',
        5 => 'xyz',
        'key' => '456',
        //bug
        "apostrophe ' xx" => 'quotes " xx',
        '\'' => "\"",
        'malicious backslash \ ' => 'double \\',
        "line break 
"
    );
$var = json_encode($var);
?>

<script>
    //bug
    var a = JSON.parse('<?php echo $var ?>');
    var b = JSON.parse("<?php echo $var ?>");
</script>

http://sandbox.onlinephpfunctions.com/code/5c860f978ddd6d196b15c58f55db20de34bcf72c

Answer 1

You dont need to parse a JSON object when it is already JSON.

remove JSON.parse()

<?php
$var = array(
        'nokey',
        5 => 'xyz',
        'key' => '456',
        //bug
        "apostrophe ' xx" => 'quotes " xx',
        '\'' => "\"",
        'malicious backslash \ ' => 'double \\',
        "line break 
"
    );
$var = json_encode($var);
?>

<script>
    //bug
    var a = <?php echo $var ?>;
    var b = <?php echo $var ?>;
</script>