TypeError：操作数e中的'in'无效

Question

我有以下代码用于显示由php文件引发的json响应，当我在控制台上显示它时，它给了我TypeError：在'操作数e中无效'

Json的回应：

[{"keyword":"free dental care","svol":27100},{"keyword":"low cost dental care","svol":2900}]

JQuery的：

$('#specialty').change(function(){
        var spevalue=$( "#specialty option:selected" ).text();
        var dataString='specialty='+ spevalue;
        $.ajax({
            type:"post", 
            datatype : 'json',
            url:"GetKeyWordBids.php", 
            data:"specialty="+ spevalue,
            success: function(data) {

                $.each(data, function( index, value ) {

                console.log(value.keyword);
                });
                },      
        });
    }); 

回应：

TypeError: invalid 'in' operand e

GetKeyWordBids.php

<?php

require_once dirname(__FILE__).'/googleads-php-lib-master/examples/AdWords/v201409/init.php';

/**
 * Runs the example.
 * @param AdWordsUser $user the user to run the example with
 */
$specialty=$_POST['specialty']; 
$ret=array();
// Include the initialization file

require_once UTIL_PATH . '/MapUtils.php';

function GetKeywordIdeasExample(AdWordsUser $user) {
    global $ret;
    $ret=array();
  // Get the service, which loads the required classes.
  $targetingIdeaService =
      $user->GetService('TargetingIdeaService', ADWORDS_VERSION);

  // Create seed keyword.
  $keyword =$_POST['specialty'];

  // Create selector.
  $selector = new TargetingIdeaSelector();
  $selector->requestType = 'IDEAS';
  $selector->ideaType = 'KEYWORD';
  $selector->requestedAttributeTypes = array('KEYWORD_TEXT', 'SEARCH_VOLUME',
      'CATEGORY_PRODUCTS_AND_SERVICES');

  // Create language search parameter (optional).
  // The ID can be found in the documentation:
  //   https://developers.google.com/adwords/api/docs/appendix/languagecodes
  // Note: As of v201302, only a single language parameter is allowed.
  $languageParameter = new LanguageSearchParameter();
  $english = new Language();
  $english->id = 1000;
  $languageParameter->languages = array($english);

  // Create related to query search parameter.
  $relatedToQuerySearchParameter = new RelatedToQuerySearchParameter();
  $relatedToQuerySearchParameter->queries = array($keyword);
  $selector->searchParameters[] = $relatedToQuerySearchParameter;
  $selector->searchParameters[] = $languageParameter;

  // Set selector paging (required by this service).
  $selector->paging = new Paging(0, AdWordsConstants::RECOMMENDED_PAGE_SIZE);

  do {

    // Make the get request.
    $page = $targetingIdeaService->get($selector);

    // Display results.
    if (isset($page->entries)) {
      foreach ($page->entries as $targetingIdea) {
        $data = MapUtils::GetMap($targetingIdea->data);
        $keyword = $data['KEYWORD_TEXT']->value;
        $search_volume = isset($data['SEARCH_VOLUME']->value)
            ? $data['SEARCH_VOLUME']->value : 0;
        $categoryIds =
            implode(', ', $data['CATEGORY_PRODUCTS_AND_SERVICES']->value);
       // printf("Keyword idea with text '%s', category IDs (%s) and average "
            //. "monthly search volume '%s' was found.\n",
           // $keyword, $categoryIds, $search_volume);
        array_push($ret,array("keyword"=>$keyword,"svol"=>$search_volume));
        //$temp=array();
        //$ret = array_merge($ret, array("keyword"=>$keyword,"svol"=>$search_volume));

        //array_push($ret,$temp);
        //$json=json_encode($temp);
        //array_push($ret,$json);

      }
      //print_r($ret);
      echo json_encode($ret); 
    }

    else {
      print "No keywords ideas were found.\n";
    }

    // Advance the paging index.
    $selector->paging->startIndex += AdWordsConstants::RECOMMENDED_PAGE_SIZE;
  } while ($page->totalNumEntries > $selector->paging->startIndex);
}


try {
  // Get AdWordsUser from credentials in "../auth.ini"
  // relative to the AdWordsUser.php file's directory.
  $user = new AdWordsUser();

  // Log every SOAP XML request and response.
    $user->LogAll();
    //$user->SetClientCustomerId(3310773561);
  // Run the example.
  GetKeywordIdeasExample($user);
} catch (Exception $e) {
  printf("An error has occurred: %s\n", $e->getMessage());
}