0是数字,是empty,是false,不是null,值相当于空字符串,但类型不是字符串,去空格或强制转换为字符串型时不等于空字符串 ""的值相当于0,是empty,是空字符串,是false,不是null,不是数字字符串 null的值相当于空字符串,值相当于0,是empty,是false,不是字符串,不是数字0 "=="只要值相等就满足条件; "==="...
"no null":"null","\r\n"; unset($b); echo "is_null","\$b",is_null($b)?"no null":"null","\r\n"; 通过上面这个简单测试,我们可以大体知道,当一个变量存在情况下:isset,empty,is_null检测,得到值情况了。上面没有举例更多变量。其实测试发现: empty 如果 变量 是非空或非零的值,则 empty...
PHP中判断变量类型及是否为空主要涉及到的函数有gettype(),isEmpty(),isset(),is_null(),下表详细说
// $arr[0];V2=FETCH_DIM_R$arrint(0)FREEV2// $arr[0] = $val;ASSIGN_DIM$arrint(0)OP_DATA$val// $arr[0] += 1;ASSIGN_ADD(dim)$arrint(0)OP_DATAint(1)// isset($arr[0]);T5=ISSET_ISEMPTY_DIM_OBJ(isset)$arrint(0)FREET5// unset($arr[0]);UNSET_DIM$arrint(0) ...
/*** 获取和设置配置参数 支持批量定义* @param string|array $name 配置变量* @param mixed $value 配置值* @param mixed $default 默认值* @return mixed*/function C($name = null, $value = null, $default = null){static $_config = array();// 无参数时获取所有if (empty($name)) {return...
These middleware will automatically trim all incoming string fields on the request, as well as convert any empty string fields to null. This allows you to not have to worry about these normalization concerns in your routes and controllers.
V5.1.23+版本开始,支持findOrEmpty方法,当查询不存在的时候返回空数组而不是Null。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 // table方法必须指定完整的数据表名 Db::table('think_user')->where('id',1)->findOrEmpty(); 如果没有查找到数据,则会抛出一个think\db\exception\DataNotFoundExce...
Calling a function on a null or otherwise unusable variable. This does not include web server errors, such as timeouts. The log will include: A timestamp of when the error occurred. The error that occurred. Thefile and line in the code for the origination of the error. ...
2return!is_null($value); 3}); In previous versions of Laravel, the$keywas passed first. Since most use cases are only interested in the$valueit is now passed first. You should do a "global find" in your application for these methods to verify that you are expecting the$valueto be ...
// return Redis::SERIALIZER_NONE, Redis::SERIALIZER_PHP, // Redis::SERIALIZER_IGBINARY, Redis::SERIALIZER_MSGPACK or Redis::SERIALIZER_JSON $redis->getOption(Redis::OPT_SERIALIZER); ping Description: Check the current connection status. Prototype $redis->ping([string $message]); Return value...