How to implement articles.json so that the latest articles are added to this file?

Question

PHP

How to implement articles.json so that the latest articles are added to this file?
How to make it output an array and the body of this array, when news is added to the database, automatically updated to the place: id name, etc.? Help who knows, thanks in advance !!! Array example :
"feed": [
{
"id": 1,
"name": "National Geographic Channel",
"image": " someaddress.com/feed/img/cosmos.jpg ",
"status": "\" Science is a beautiful and emotional human endeavor,\" says Brannon Braga, executive producer and director. \"And Cosmos is all about making science an experience.\"",
"
"timeStamp": "1403375851930",
"url": null
}

Answer 1

file get contents
json decode
array[] = article
json encode
file put contents

Answer 2

In php, I understood in some.json itself I did not understand how to implement it)))