How to serialize an object into a JSON string? 
let person = {
    "firstName" : "Alice",
    "lastName" : "Jones"
};
console.log(person);

/* output: 
{ firstName: 'Alice', lastName: 'Jones' }
*/

let personString = JSON.stringify(person);
console.log(personString);

/* output: 
{"firstName":"Alice","lastName":"Jones"}
*/
How to deserialize a JSON string into an object? 
let personParsed = JSON.parse(personString);