if(empty($row))//开始判断是够为空 { echo "null"; } else { echo "not null"; } 方法二: $sql = "select * form abc" $result = mysql_query($sql); $row = mysql_fetch_array($result); if(!$row)//开始判断是够为空 { echo "null"; } else { echo "not null"; } /***/ 其...
这意味着,我们在使用变量处理函数时,当该变量可能出现0的值,使用 empty 要小心,这个时候用 isset 取代它更明智一些。 当一个php页面的 URL 尾部参数出现 id=0 时(比如:test.php?id=0),试比较: if(empty($id)) $id=1; // 若 id=0 ,id 也会为1 if(!isset($id)) $id=1; // 若 id=0 ,id...
7.empty函数 判断变量是否为空,0 "" "0" false array() null 没有定义 这7种都为空的情况 8.变量类型测试函数 代码语言:javascript 代码运行次数:0 复制 Cloud Studio代码运行 整型is_int();浮点型is_float();字符型is_string();布尔型is_bool();数组is_array();对象is_object();资源is_resource();...
function custom_download_url($url, $destination_directory) {// 获取上传目录信息$upload_dir = wp_upload_dir();// 确保上传目录存在且可写if (!is_dir($upload_dir[‘path’]) || !is_writable($upload_dir[‘path’])) {return new WP_Error(‘upload_dir_not_writable’, ‘上传目录不存在或不...
echo '$var is either 0 or not set at all'; } // 结果为 false,因为 $var 已设置 if (!isset($var)) { echo '$var is not set at all'; } ?> 注: 由于这是一个语言结构而非函数,因此它无法被变量函数调用。 注: empty() 只检测变量,检测任何非变量的东西都将导致解析错误。换句话说,后...
Fatal error: Default value for property of type int may not be null. Use the nullable type ?int to allow null default value in /path/to/dir/Test.class.php on line 5 Write session: before|i:0; If you uncomment the second require_once so that the autoloader doesn't need to run...
* - If the Host header is missing or empty, and the new URI does not contain a * host component, this method MUST NOT update the Host header in the returned * request. * - If a Host header is present and non-empty, this method MUST NOT update * the Host header in the returned ...
('php://input'), $_PUT);}$input = $_PUT;break;default:$input = $_GET;}break;case 'path' :$input = array();if(!empty($_SERVER['PATH_INFO'])){$depr = C('URL_PATHINFO_DEPR');$input = explode($depr,trim($_SERVER['PATH_INFO'],$depr));}break;case 'request' :$input =...
邻接矩阵的广度优先遍历: BFS(G) for i=0;i<G->numVertexes;i++ visited[i]=false;//检测是否访问过 for i=0;i<G.numVertexes;i++//遍历顶点 if visited[i]==true break;//访问过的断掉 visited[i]=true //当前顶点访问 InQueue(i) //当前顶点入队列 while(!QueueEmpty()) //当前队列不为...
}if(empty($error)) {//var_dump($movie_rating); //注意是movie_type不是mvioe_type,大错特错$query= 'insert into movie(movie_name,movie_year,movie_type,movie_leadactor,movie_director,movie_release,movie_rating) values("'.$movie_name.'",'.$movie_year.','.$movie_type.','.$movie_lead...