te')); return $arr; } /* 遍历用户所有主题 * @param $uid 用户ID * @param int $page 页数 * @param int $pagesize 每页记录条数 * @param bool $desc 排序方式 TRUE降序 FALSE升序 * @param string $key 返回的数组用那一列的值作为 key * @param array $col 查询哪些列 */ function thread_tid_find_by_uid($uid, $page = 1, $pagesize = 1000, $desc = TRUE, $key = 'tid', $col = array()) { if (empty($uid)) return array(); $orderby = TRUE == $desc ? -1 : 1; $arr = thread_tid__find($cond = array('uid' => $uid), array('tid' => $orderby), $page, $pagesize, $key, $col); return $arr; } // 遍历栏目下tid 支持数组 $fid = array(1,2,3) function thread_tid_find_by_fid($fid, $page = 1, $pagesize = 1000, $desc = TRUE) { if (empty($fid)) return array(); $orderby = TRUE == $desc ? -1 : 1; $arr = thread_tid__find($cond = array('fid' => $fid), array('tid' => $orderby), $page, $pagesize, 'tid', array('tid', 'verify_date')); return $arr; } function thread_tid_delete($tid) { if (empty($tid)) return FALSE; $r = thread_tid__delete(array('tid' => $tid)); return $r; } function thread_tid_count() { $n = thread_tid__count(); return $n; } // 统计用户主题数 大数量下严谨使用非主键统计 function thread_uid_count($uid) { $n = thread_tid__count(array('uid' => $uid)); return $n; } // 统计栏目主题数 大数量下严谨使用非主键统计 function thread_fid_count($fid) { $n = thread_tid__count(array('fid' => $fid)); return $n; } ?>Assign empty string to javascript variable - Stack Overflow

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    Assign empty string to javascript variable - Stack Overflow

    programmeradmin4浏览0评论

    I get return value as null and assign that value it shows as null in the UI. But I want to check some condition and if it is null, it should not show up anything.. I tried the below code and it doesn't work

    var panyString;
if(utils.htmlEncode(itempanyname) == null)
{
  panyString = '';
}
else{
  panyString = utils.htmlEncode(itempanyname);
}

    I get return value as null and assign that value it shows as null in the UI. But I want to check some condition and if it is null, it should not show up anything.. I tried the below code and it doesn't work

    var panyString;
if(utils.htmlEncode(item.panyname) == null)
{
  panyString = '';
}
else{
  panyString = utils.htmlEncode(item.panyname);
}

    • javascript
    Share Improve this question asked Jul 24, 2015 at 4:15 Vetri ManoharanVetri Manoharan 511 gold badge1 silver badge5 bronze badges 2
    • why don't you just do var panyString=" "? – Guruprasad J Rao Commented Jul 24, 2015 at 4:17
    • You should pare item.panyname to null (but probably really any false-y value), not the encoded form. – user2864740 Commented Jul 24, 2015 at 4:25
    Add a ment  | 

    3 Answers 3

    Reset to default 5

    Compare item.panyname to null (but probably really any false-y value) - and not the encoded form.

    This is because the encoding will turn null to "null" (or perhaps "", which are strings) and "null" == null (or any_string == null) is false.

    Using the ternary operator it can be written as so:

    var panyString = item.panyname
  ? utils.htmlEncode(item.panyname)
  : "";

    Or with coalescing:

    var panyString = utils.htmlEncode(item.panyname ?? "");

    Or in a long-hand form:

    var panyString;
if(item.panyname) // if any truth-y value then encode
{
  panyString = utils.htmlEncode(item.panyname);
}
else{                // else, default to an empty string
  panyString = '';
}

    var panyString;
if(item.panyname !=undefined &&   item.panyname != null ){
panyString = utils.htmlEncode(item.panyname);  
}
else{
panyString = '';
}

    Better to check not undefined along with not null in case of javascript. And you can also put alert or console.logto check what value you are getting to check why your if block not working. Also, utls.htmlEncode will convert your null to String having null literal , so pare without encoding.

    var panyString="";
if(utils.htmlEncode(item.panyname) != null)
{
   panyString = utils.htmlEncode(item.panyname);
}

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