Can anyone explain this PHP code using json_encode and json_decode?
Question
$a = '{ "tag": "<b></b>" }';
echo json_encode( json_decode($a) );
This outputs:
{"tag":"<b><\/b>"}
when you would think it would output exactly the input. For some reason json_encode adds an extra slash.
Solution
Because it's part of the JSON standard
char
any-Unicode-character- except-"-or-\-or- control-character \" \\ \/ <---- see here? \b \f \n \r \t \u four-hex-digits
OTHER TIPS
use this:
echo json_encode($a,JSON_HEX_TAG)
Result will be:
["\u003C\u003E"]
You can read this article to improve your knowledge about JSON_ENCODE http://php.net/manual/en/function.json-encode.php
That's probably a security-feature. The escaped version (Eg. the output) would be parsed as similar to the unescaped-version, by Javascript (Eg. \/
becomes /
). Having escaped the slash like that, there is a lesser chance of the browser misinterpreting the Javascript-string as HTML. Of course, if you treat the data correct, this shouldn't be needed, so it's more a safeguard against a clueless programmer messing things up for himself.
Your input is not valid JSON, but PHP's JSON parser (like most JSON parsers) will parse it anyway.