<?php
# PHP object -> JSON string
$json_string = json_encode(['my_key' => 'my value', 'other_key' => 'other value']);
echo $json_string;

# JSON string -> PHP object
$json_string = '{"my_key":"my value","other_key":"other value"}';
$my_array =  json_decode($json_string);
print_r($my_array)

// Dump/read from file
file_put_contents('test.json', json_encode([2, 4, 6]));
$my_array = json_decode(file_get_contents('test.json'));
print_r($my_array);