how to receive json data in php

1//Json Encode
2
3$person = array( 
4    "name" => "KINGASV", 
5    "title" => "CTO"
6); 
7$personJSON=json_encode($person);//returns JSON string
8
9//Json Decode
10
11$personJSON = '{"name":"KINGASV","title":"CTO"}';
12
13$person = json_decode($personJSON);
14
15echo $person->name; // KINGASV
16

1header('Content-type: application/json');
2echo json_encode($array);

1<?php
2
3$data = '{
4	"name": "Aragorn",
5	"race": "Human"
6}';
7
8$character = json_decode($data);
9echo $character->name;

1$data = json_decode(file_get_contents('php://input'), true);
2print_r($data);
3echo $data;
4

1<?php
2$jsonurl = "https://reqres.in/api/users/2";
3$json = file_get_contents($jsonurl);
4$jsonDecode = json_decode($json, true);
5echo $jsonDecode['data']['email'];
6?>

1//code igniter
2$query="qry";
3$query = $this->db->query($query);
4$res=$query->result();
5return json_encode($res);