How do JSON.parse() and escape characters work in JavaScript?

Question

Suppose I have an object variable:

var obj = { key: '\"Hello World\"' }

Then I tried parse it to string by using JSON.stringify in Chrome devtools console:

JSON.stringify(obj) // "{"key":"\"Hello World\""}"

I get the result "{"key":"\"Hello World\""}". Then I give it to a string

var str = '{"key":"\"Hello World\""}'

At least I try to convert it back to obj:

JSON.parse(str);

but the browser tell me wrong Uncaught SyntaxError

What confused me is why this is wrong? I get the string from an origin object and I just want turn it back.

How can I fix this problem? If I want do the job like convert obj to string and return it back, how can I do?

You might find what you're doing easier if you don't use \ to escape characters in this case. If you alternate between ' and " you don't need to escape. For example, you can do key: '"Hello World"'. — Jo Sprague
– Jo Sprague, Commented Dec 23, 2015 at 15:34
A string value is not the same as a string literal. JSON.parse(JSON.stringify(obj)) will work just fine. — Felix Kling
– Felix Kling, Commented Dec 23, 2015 at 15:37

Quentin · Accepted Answer · 2015-12-23 15:26:40Z

You're tried to convert your JSON into a string literal by wrapping it in ' characters, but \ characters have special meaning inside JavaScript string literals and \" gets converted to " by the JavaScript parser before it reaches the JSON parser.

You need to escape the \ characters too.

var str = '{"key":"\\"Hello World\\""}'

That said, in general, it is better to not try to embed JSON in JavaScript string literals only to parse them with JSON.parse in the first place. JSON syntax is a subset of JavaScript so you can use it directly.

var result = {"key":"\"Hello World\""};

leguano · Accepted Answer · 2015-12-23 15:28:26Z

0

try:

var str = '{"key":"\\"Hello World\\""}';

answered Dec 23, 2015 at 15:28

leguano

1711 silver badge6 bronze badges

Collectives™ on Stack Overflow

How do JSON.parse() and escape characters work in JavaScript?

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related