C＃序列化JSON将\\变成\\\\\\\\

Question

I am generating JSON for inclusion direction into a HTML file and as such the JSON gets wrapped in a Javascript String.

eg

var dataContacts = 
        '{"Contacts":[{"Id":0,"Active":false,"Company":"Rory The Architect\\, Melt"}]}';

var contacts = $.parseJSON(dataContacts).Contacts;

This code FAILS in javascript because it should be

var dataContacts = 
        '{"Contacts":[{"Id":0,"Active":false,"Company":"Rory The Architect\\\\, Melt"}]}';

var contacts = $.parseJSON(dataContacts).Contacts;

I've used both .NET Serializer and NewtonSoft.Json and neither have support for turning a \\ into a \\\\\\\\, they do offcourse turn the \\ into a \\\\ which would be fine for AJAX delivery of JSON but not for JSON embbeded in a Javascript String

I assume I may need to do some sort of myJson.Replace("\\", "\\\\");

I've looked at why I need a \\\\ in the output, see this link here:

Why does the jQuery JSON parser need double escaping for backslashes?

The first escape escapes it in the Javascript string literal. The second escape escapes it in the JSON string literal.

The Javascript expression '{"a":"b:\\c"}' evaluates to the string '{"a":"b:\\c"}'. This string contains a single unescaped \\, which must be escaped for JSON. In order to get a string containing \\, each \\ must be escaped in the Javascript expression, resulting in "\\\\".

I am wondering the best path forward on this issue and why neither NewtonSoft or the .NET serializer have support for encoding JSON for inclusion directly into the Javascript file

Answer 1

It looks to me like you're causing yourself undue trouble by doing things the hard way. Why are you putting JSON into a JavaScript string just so you can immedately parse it? The JSON is already JavaScript, so why not just use it?

var dataContacts = 
       {"Contacts":[{"Id":0,"Active":false,"Company":"Rory The Architect\\, Melt"}]};

var contacts = dataContacts.Contacts;

And as Paul Draper points out, the approach you're tring to use provides all sort of extra complications once apostrophes and other characters start getting involved.

Answer 2

There is actually a second problem here as well, which you have not identified: What if the JSON includes a single quote ( ' ), eg Rory's Architect ?

Not only with the Javscript string not be valid JSON, it won't even be valid Javascript !

var dataContacts = 
    '{"Contacts":[{"Id":0,"Active":false,"Company":"Rory's Architect\\, Melt"}]}';

To resolve this, you can do (in C#)

string myJsonString = myJson.Replace("\\", "\\\\").Replace("'", "\\'")

Note that the escaping the backslashes was necessary in C# to get \\ , \\\\ , and \\' . It's a lot of escaping, all around ;)