keep a json format after to do a stringify code example

Example 1: json.stringify parameters

var person={"first_name":"Tony","last_name":"Hawk","age":31};
console.log(JSON.stringify(person , null , 4)); 
//Output:
> "{
    "first_name": "Tony",
    "last_name": "Hawk",
    "age": 31
}"

Example 2: node json stringify

let data = {
  name: "John Smith",
  age: 30,
  hobbies: ["Programming", "Video Games"]
};

// {name:"John Smith",age:30,hobbies:["Programming","Video Games"]}
let miny = JSON.stringify(data);

// The 4 parameter signifys 4 spaces. You can also use "\t".
/* {
 *     name: "John Smith",
 *     age: 30,
 *     ...
 */
let pretty = JSON.stringify(data, null, 4);