how to use json response in php code example

Example 1: php return json

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

Example 2: return json in php

//code igniter
$query="qry";
$query = $this->db->query($query);
$res=$query->result();
return json_encode($res);

Example 3: how to make a json request in php

<?php
$jsonurl = "http://api.wipmania.com/json";
$json = file_get_contents($jsonurl);
var_dump(json_decode($json));
?>