Parsing a JSON string in javascript

Question

I encountered a weird behaviour of JSON.parse method in javscript.

If you pass it a string in quotes like - "\"I am a random string\""

Instead of throwing an error it will parse the string and return the same

var a = '"I am a random string"';

var b = JSON.parse(a); // no error, parsing is successful

console.log(b); // output "I am a random string"

I am wondering what could be the cause of this? Is a string in quotes considered a valid JSON object?

That's how you encode a string in JSON, yes. From json.org: A string is a sequence of zero or more Unicode characters, wrapped in double quotes — Heretic Monkey
– Heretic Monkey, Commented May 4, 2017 at 17:42
It's not an object but a string. "foo bar" is how strings are encoded in JSON. There doesn't have to be an object or array at the top level. Any value is fine. JSON.parse('null'), JSON.parse('true'), etc are all valid too. — Felix Kling
– Felix Kling, Commented May 4, 2017 at 17:42
Also, there's no such thing as a JSON object. Your variable a contains a string, which, if interpreted in JSON format, is a valid string. Now if you try var a = "I am a random string"; var b = JSON.parse(a);, you'll get an error. — Heretic Monkey
– Heretic Monkey, Commented May 4, 2017 at 17:45

Community · Accepted Answer · 2021-10-07 10:55:51Z

1

According to the JSON Specification, a JSON text is any serialized value. Any of the following value types is valid JSON:

Quoting directly from the grammar in the spec:

  value = false / null / true / object / array / number / string

JSON.parse() can deserialize any kind of value listed above, not just Objects.

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answered May 4, 2017 at 18:10

salezica

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