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; } ?>syntax - What is the opposite of ("key" in obj ) in javascript? - Stack Overflow

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    This might seem very easy, but here is my question,what is the opposite of 

    if('name' in obj)

    Is it if(!'name' in obj) or if("name" not in obj) or something else?

    Thanks!

    This might seem very easy, but here is my question,what is the opposite of 

    if('name' in obj)

    Is it if(!'name' in obj) or if("name" not in obj) or something else?

    Thanks!

    • javascript
    • syntax
    Share Improve this question edited Dec 21, 2011 at 0:47 sammiwei asked Dec 21, 2011 at 0:38 sammiweisammiwei 3,2009 gold badges42 silver badges53 bronze badges
    Add a ment  | 

    5 Answers 5

    Reset to default 13

    just wrap it in parens:

    if( !( 'name' in obj ) ){

    It would be like this:

    if (!('name' in obj)) {
    // 'name' not found in obj
}

    "name" in obj is just a boolean expression, just like a && b || c. You can negate it like any other expression: !("name" in obj).

    there are a few ways, like:

    if (!('name' in obj))
if (Object.keys(obj).indexOf('name')<0)

    You may want:

    if (obj.hasOwnProperty(propName))

    which checks for a property on the object itself. To include inherited properties, other answers using the in operator will do.

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