JSON stringify objects with json strings already as values

Question

Might be a duplicate question, but couldn't find the answer. I want to stringify a javascript object that contains some JSON strings as values.

For example:

var obj = {id:1, options:"{\"code\":3,\"type\":\"AES\"}"};

As you see, the value for key 'options' is a JSON string. I want to stringify the object 'obj', without double stringifying the inner JSON string.

Is there any clean and neat solution for this, except parsing each value with JSON string and stringifying the object?

Answer 1

Assuming you don't know which properties are JSON, you could use the replacer function parameter on JSON.stringify to check if a value is a JSON string. The below example tries to parse each string inside a try..catch , so is not the most efficient, but should do the trick (on nested properties as well)

var obj = {id:1, options:"{\"code\":3,\"type\":\"AES\"}"};

function checkVal(key,val){
	if(typeof val === 'string'){
		try{return JSON.parse(val);}catch(e){}
  }
  return val;
}

var res = JSON.stringify(obj,checkVal);

console.log('normal output', JSON.stringify(obj))
console.log('with replacer', res);

Answer 2

No, you can't do that.
If you did not encode that string, JSON.parse will not return a correct string.

The cleanest solution to do that is use JSON for obj.options, and stringify it when you need to use it.