JQuery.each'undefined'如何使用它

Question

我是这个功能的新手，我今天才被介绍给我。我正在尝试将用户名称显示在我的Feed中，因为它表示未定义。我不知道如何使用此功能使其正常工作。任何提示都会有很大帮助。

success: function(response){
    // Streams
    $.each(response.streams, function(i, stream) {
      $("#articles").prepend("<div id='divider-"+stream['streamitem_id']+"'><div class='userinfo'><a href='/profile.php?username="+stream['username']+"'><img class='stream_profileimage' style='border:none;padding:0px;display:inline;' border=\"0\" src=\"imgs/cropped"+stream['id']+".jpg\" onerror='this.src=\"img/no_profile_img.jpeg\"' width=\"40\" height=\"40\" ></a><div class'delete' style='cursor:pointer;position:relative;top:0px;float:right;padding-right:5px;' onclick=\"delete_('"+stream['streamitem_id']+"');\">X</div><a href='/profile.php?username="+stream['username']+"'>"+stream['first']+" "+ stream['middle']+" "+stream['last']+"</a><span class='subtleLink'> said</span><br/><a class='subtleLink' style='font-weight:normal;'>"+stream['streamitem_timestamp']+"</a><hr>"+stream['streamitem_content']+"<div style='height:20px;' class='post_contextoptions'><div id='streamcomment'><a style='cursor:pointer;' id='commenttoggle_"+stream['streamitem_id']+"' onclick=\"toggle_comments('comment_holder_"+stream['streamitem_id']+"');clearTimeout(streamloop);swapcommentlabel(this.id);\">Write a comment...</a></div><div id='streamlike'><a title='Like "+stream['first']+" "+ stream['middle']+" "+stream['last']+"s status' id='likecontext_"+stream['streamitem_id']+"' style='cursor:pointer;' onClick=\"likestatus("+stream['streamitem_id']+",this.id);\"><div style='width:50px;' id='likesprint"+stream['streamitem_id']+"'>Like</a></div><div style='width:50px;' id='likesprint"+stream['streamitem_id']+"'><a title='See who likes "+stream['first']+" "+ stream['middle']+" "+stream['last']+"s status' href='include/likes.php?streamitem_id="+stream['streamitem_id']+"' /></a></div></div></form></div><div id='streamdislike'><a id='dislikecontext_"+stream['streamitem_id']+"' style='cursor:pointer;' onClick=\"dislikestatus("+stream['streamitem_id']+",this.id);\"><div style='width:70px;' id='dislikesprint"+stream['streamitem_id']+"'>Dislike</a></div><div style='width:70px;' id='dislikesprint"+stream['streamitem_id']+"'></div></div></form><div class='stream_comment_holder' style='display:none;' id='comment_holder_"+stream['streamitem_id']+"'><div id='comment_list_"+stream['streamitem_id']+"'></div><div class='stream_comment_inputarea'><form id='mycommentform' method='POST'  class='form_statusinput'>\
<input type='hidden'  name='streamidcontent' id='streamidcontent' value='"+stream['streamitem_id']+"'>\
<input type='input' name='commentingcontents' id='commentingcontents' placeholder='Say something' autocomplete='off'>\
<input type='submit' id='button' value='Feed'><br/></div></div>").show();
    });
  // Comments
    $.each(response.comments, function(i, comment) {

    });

 // Users
    $.each(response.users, function(i, user) {

    });

HERE是我的php拆分中的JSON

$call="SELECT * FROM streamdata WHERE streamitem_id < '$lastID' AND streamitem_target=".$following_string." OR streamitem_creator=".$following_string." ORDER BY streamitem_id DESC LIMIT 10";
$chant = mysqli_query($mysqli, $call) or die(mysqli_error($mysqli));
$json = array();
$json['streams'] = array();

while ($resultArr = mysqli_fetch_assoc($chant)) {
    $arr = array();
    $arr['streamitem_id'] = $resultArr['streamitem_id'];
    $arr['streamitem_content'] = $resultArr['streamitem_content'];
    $arr['streamitem_timestamp'] = Agotime($resultArr['streamitem_timestamp']);

    $json['streams'][] = $arr;
}

/***** COMMENTS *****/
$check = "SELECT comment_id, comment_datetime, comment_streamitem, comment_poster, comment_content FROM streamdata_comments WHERE comment_poster=".$following_string."  ORDER BY comment_datetime DESC";
$check1 = mysqli_query($mysqli,$check);
$json['comments'] = array();

while ($resultArr = mysqli_fetch_assoc($check1)) {
    $arr = array();
    $arr['comment_id'] = $resultArr['comment_id'];
    $arr['comment_content'] = $resultArr['comment_content'];
    $arr['comment_poster'] = $resultArr['comment_poster'];
    $arr['comment_datetime'] = Agotime($resultArr['comment_datetime']);
    $arr['comment_streamitem'] = $resultArr['comment_streamitem'];

    $json['comments'][] = $arr;
}

/***** USERS *****/

$check = "SELECT * FROM users WHERE id=".$following_string."";
$check1 = mysqli_query($mysqli,$check);
$json['users'] = array();

while ($resultArr = mysqli_fetch_assoc($check1)) {
    $arr = array();
    $arr['username'] = $resultArr['username'];
    $arr['id'] = $resultArr['id'];
    $arr['first'] = $resultArr['first'];
    $arr['middle'] = $resultArr['middle'];
    $arr['last'] = $resultArr['last'];

    $json['users'][] = $arr;
}


echo json_encode($json);
}
?>