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Why doesn't my attempt to escape quotation marks in JSON work?

I am parsing a JSON-string with the JQuery.parseJSON function, as I have done lot's of times in my code. On this particular case, though, I get: Uncaught SyntaxError: Unexpected token R. The only upper case R that exists, in my JSON-formatted String, comes right after an escaped quotation mark, ... \"R ... like this. It seems like too much of a coincidence to be caused by anything other than this, but as far as I can tell, I have completely followed the proper syntax as described on json.org.
EDIT:
I've tried to manually remove the occurrances of \" in a hardcoded test, and the string formats perfectly into a proper Javascript object. In other words, my \" is definitely the problem here...
var myObject = $.parseJSON(myString);
EDIT 2:
the problematic area of my String is here displayed, both in working, and not working condition. first the problematic one:
{"lineID":33,"boxID":10,"title":"My text with the \"Ruining Part\""}
Then the working one:
{"lineID":33,"boxID":10,"title":"My text with the Ruining Part"}
Finally how i format my javabean object into JSON string.
String jsonObjectAsString = new Gson().toJson(myJavaBeanObject);

You probably need to escape the backslash in your string, if it is hardcoded, so that the final string that gets parsed has a single backslash followed by a double quote. Otherwise, the browser thinks you are trying to escape a double quote in your string, which does nothing.
So change your string to:
...\\"R...

RegExp for remove first and last char and turn ending double slashes into single

I have the following Javascript code to obtain the inner string from an RegExp:
Function.prototype.method = function (name,func){
this.prototype[name] = func;
return this;
};
RegExp.method('toRawString', function(){
return this.toString().replace(/^.(.*).$/,"$1");
});
The purpose of this, is to avoid in string double quoting. For example, if you have a Windows file path "C:\My Documents\My Folder\MyFile.file", you can use it like the following:
alert(/C:\My Documents\My Folder\MyFile.file/.toRawString());
However it is not working for ""C:\My Documents\My Folder\" since it causes syntax error. The only way to avoid it is to keep double quoting at the end of the string. Thus it will be written
alert(/C:\My Documents\My Folder\\/.toRawString());
The fact is any odd number of back slashes on the end of the string will be an error, so all ending back slashes must be double escaped. It will not be hard to use a multiple line small implementation, but are there any single RegExp solution?
NOTE
When using toRawString the RegExp object for this is usually NOT going to be used for any other purpose except for that method. I just want to use the syntax of RegExp to avoid double back slashes in source code. Unfortunately the ending double slashes cannot be easily avoid. I think another workaround is to force a space at the end but that is another question then.
UPDATE
I finally solved the "another question" and posted the code here.

OK, I get what you're trying to do! It's hacky : )
Try something like:
return this.toString().slice(1, -1).replace(/\\+$/, '\\')
Hope that helps.

If you want to include the double quotes in the string just wrap it with single quotes.
s = '"C:\\My Documents\\My Folder\\MyFile.file"'
console.log(s) // Output => "C:\My Documents\My Folder\MyFile.file"

This produces a syntax error:
/C:\My Documents\/
But that regular expression could be written correctly like this:
/C:\\My Documents\\/
Or like this:
new RegExp("C:\\\\My Documents\\\\")
I think your function is just fine and is returning a correct result. Regular expressions just can't end with an unpaired backslash. It's not that you're double escaping - you're just escaping the escape character.
This would produce an error too:
new RegExp("C:\\My Documents\\")
A regular expression like this, for instance, can't be written without a pair of backslashes:
/C:\\What/
Without the second backslash, \W would be interpreted as a special character escape sequence. So escaping the escape character isn't only necessary at the end. It's required anywhere it might be interpreted as the beginning of an escape sequences. For that reason, it might be a good rule of thumb to always use two backslashes to indicate a backslash literal in a regular expression.

carriage return encoding

through queries to a Database I am retrieving such data that I previously inserted through HTML textarea or input. When I get the response from my DB , in a JSON object the text field looks like this :
obj : {
text : [some_text] ↵ [some_text]
}
I tried to replace with this function :
string_convert = function(string){
return string.replace("&#8629",'<br>')
.replace('&crarr','<br>')
.replace('/[\n\r]/g','<br>');
}
I have to show this string in HTML ,but it does not seems to work. I'm using UTF-8
Any advice?

The problem you have is that you have enclosed your regex in quotes. This is incorrect.
.replace('/[\n\r]/g','<br>');
^ ^
remove these two quotes
The quotes are unnecessary because the regex is already delimited by the slashes.
By putting quotes in there, you've actually told it that you want to replace a fixed string rather than a regular expression. The fixed string may look like an expression, but with the quotes, it will just be seen as a plain string.
Remove the quotes and it will be seen as an expression, and it will work just fine.
One other thing, though -- in order to make your regex work perfectly, I'd also suggest modifying it slightly. As it stands, it will just replace all the \n and \r characters with <br>. But in some cases, they may come together as a \r\n pair. This should be a single line break, but your expression will replace it with two <br>s.
You could use an expression like this instead:
/\r\n|\n|\r/g
Hope that helps.

you are missing the ending semicolons ; in your code:
string_convert = function(aString){
return aString.replace("↵",'<br>').replace('↵','<br>');
}
this does not necessary solve your problem, but it could likely.

From: Trying to translate a carriage return into a html tag in Javascript?
text = text.replace(/(\r\n|\n|\r)/g,"<br />");

Escape single quote with JavaScript

I am aware with escaping special characters in HTML.
But, I am still asking this as I have come across a situation.
I have a JSP, in which I am not allowed put validation on input. Users are entering special characters to test.
Input string:
'##$%
When I am displaying from database, I am using
<%= StringEscapeUtils.escapeHtml(map[i].get("text").toString())%>
where "map" is an array of Hashmap. This works fine.
The problem comes when I need to pass this string to JavaScript using
<input type="Button"
onclick="onEdit('<%= StringEscapeUtils.escapeHtml(map[i].get("text").toString())%>',
'<%= strShortCut%>','<%= map[i].get("uid")%>')" value="Edit">
The string becomes ''##$%'.
How do I escape a single quote?

If you would be using Java, maybe you can do the below in Java.
import org.apache.commons.lang.StringEscapeUtils;
...
String result = StringEscapeUtils.escapeJavaScript(jsString);

Just prepend every single quote with a backslash. Like the following:
StringEscapeUtils.escapeHtml(map[i].get("text").toString()).replace("\'","\\'")
But your problem is not only in the single quote. There is also the double quote (") and the backslash itself (\).
Use the same technique as shown before. You can also use regular expressions, but I showed you the simplest way.
To check the escape characters, look at the URL http://docs.oracle.com/javase/tutorial/java/data/characters.html.

How to add "\" character in JSON?

I want to add JSON data with the following string value:
json = "d:\xyz\abc";
This value is coming from a database at runtime. When I am going to display it in datatable, JSON formatting error is displayed. My requirement is that the above value will be displayed as it is in the datatable. Please help.

Escape it with another \:
var json = "d:\\xyz\\abc";

You'd better use a JSON library for your programming language. You don't retrieve database values directly with jquery, aren't you?
So, you'd use something like JSON.escape(my_string_from_db), or, in Ruby language I usually do my_string.to_json.
This will automatically escape everything that needs to be escaped.

Change to this:
json = "d:\\xyz\\abc";
See this question for further information

\ is the escape character in JavaScript strings, it gives special meaning to the character following the slash. Like \t is a tab character, \n is a new line. To put a backslash literal you'll need to use \\
The first backslash says the next character is going to be special, the following backslash says "oh, it's just a backslash."