将PHP编写成Javascript或Javascript到PHP中

$php_array = array('apple', 'banana', 'orange');
$json_string = json_encode($php_array);
echo $json_string;

var json_string = '<?php echo $json_string; ?>';
var js_array = JSON.parse(json_string);
console.log(js_array);

var js_array = ['apple', 'banana', 'orange'];
var json_string = JSON.stringify(js_array);

$json_string = $_POST['json_string'];
$php_array = json_decode($json_string);
print_r($php_array);

var xhr = new XMLHttpRequest();
xhr.open('POST', 'process.php');
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    var response = JSON.parse(xhr.responseText);
    console.log(response);
  }
};
var js_array = ['apple', 'banana', 'orange'];
var json_string = JSON.stringify(js_array);
xhr.send(json_string);

$json_string = file_get_contents('php://input');
$php_array = json_decode($json_string);
$response = ['status' => 'success', 'data' => $php_array];
echo json_encode($response);