gistfile1.php

<?php
  // 5.2.6
  var_dump(json_decode('{"_urls": ["a", "b"]}'));
  var_dump(json_decode('{"_urls": ["a", "b"]}', true));
  var_dump(json_decode('{"_urls": ["a", "b"]}', false));
?>

object(stdClass)#9 (1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}
array(1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}
object(stdClass)#9 (1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}

<?php
  // 5.2.10
  var_dump(json_decode('{"_urls": ["a", "b"]}'));
  var_dump(json_decode('{"_urls": ["a", "b"]}', true));
  var_dump(json_decode('{"_urls": ["a", "b"]}', false));
?>

object(stdClass)#140 (1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}
object(stdClass)#140 (1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}
object(stdClass)#140 (1) {
  ["_urls"]=>
  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
}