Stringifying strings

stringificated.js

var blah = { foo: "bar", neat: "true", something: "{\"cool\": \"not\"}"}
// { foo: 'bar',
//  neat: 'true',
//  something: '{"cool": "not"}' }
// So far, so good.

var stringified = JSON.stringify(blah)
// '{"foo":"bar","neat":"true","something":"{\\"cool\\": \\"not\\"}"}'
// Not what we wanted, but this is reasonable and expected.

// SO...what if we just started out as a string and escaped the contained JSON?
var ugh = '{ "foo": "bar", "neat": "true", "something": "{\"cool\": \"not\"}"}'
// '{ "foo": "bar", "neat": "true", "something": "{"cool": "not"}"}'
// (╯°□°）╯︵ ┻━┻

var blah = { foo: "bar", neat: "true" }
blah['something'] = JSON.parse( "{"cool": "not"}"})

// { foo: 'bar',
// neat: 'true',
// something: '{"cool": "not"}' }
// So far, so good.

var stringified = JSON.stringify(blah)
// '{"foo":"bar","neat":"true","something":"{"cool": "not"}"}'
// Not what we wanted, but this is reasonable and expected.

// SO...what if we just started out as a string and escaped the contained JSON?
var ugh = '{ "foo": "bar", "neat": "true", "something": "{"cool": "not"}"}'
// '{ "foo": "bar", "neat": "true", "something": "{"cool": "not"}"}'
// (╯°□°）╯︵ ┻━┻

You need to escape the backslashes in ugh, too. They will be evaluated as escaping the "s while the string is being interpreted and because that is not needed they will be lost. You need them to survive so that the JSON is well-formed.

var ugh = '{ "foo": "bar", "neat": "true", "something": "{\\"cool\\": \\"not\\"}"}'
// '{ "foo": "bar", "neat": "true", "something": "{\\"cool\\": \\"not\\"}"}'
JSON.parse(ugh)
// { foo: 'bar',
//  neat: 'true',
//  something: '{"cool": "not"}' }