PHP 可用的函数

清疚 2024-04-07 14:16 29阅读 0赞

HP 提供了很多可用的标准函数，下表列出了常用的几个：

<table> 
 <tbody> 
  <tr> 
   <th>函数</th> 
   <th>描述</th> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-boolval-function.html" title="boolval" rel="nofollow">boolval</a></td> 
   <td>获取变量的布尔值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-debug_zval_dump-function.html" title="debug_zval_dump" rel="nofollow">debug_zval_dump</a></td> 
   <td>查看一个变量在zend引擎中的引用计数、类型信息</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-floatval-function.html" title="doubleval" rel="nofollow">doubleval</a></td> 
   <td>floatval 的别名</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-empty-function.html" title="empty" rel="nofollow">empty</a></td> 
   <td>检查一个变量是否为空</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-floatval-function.html" title="floatval" rel="nofollow">floatval</a></td> 
   <td>获取变量的浮点值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-get_defined_vars-function.html" title="get_defined_vars" rel="nofollow">get_defined_vars</a></td> 
   <td>返回由所有已定义变量所组成的数组</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-get_resource_type-function.html" title="get_resource_type" rel="nofollow">get_resource_type</a></td> 
   <td>返回资源（resource）类型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-gettype-function.html" title="gettype" rel="nofollow">gettype</a></td> 
   <td>获取变量的类型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-import_request_variables-function.html" title="import_request_variables" rel="nofollow">import_request_variables</a></td> 
   <td>将 GET／POST／Cookie 变量导入到全局作用域中</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-intval-function.html" title="intval" rel="nofollow">intval</a></td> 
   <td>获取变量的整数值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_array-function.html" title="is_array" rel="nofollow">is_array</a></td> 
   <td>检测变量是否是数组</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_bool-function.html" title="is_bool" rel="nofollow">is_bool</a></td> 
   <td>检测变量是否是布尔型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_callable-function.html" title="is_callable" rel="nofollow">is_callable</a></td> 
   <td>检测参数是否为合法的可调用结构</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_float-function.html" title="is_double" rel="nofollow">is_double</a></td> 
   <td>is_float 的别名</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_float-function.html" title="is_float" rel="nofollow">is_float</a></td> 
   <td>检测变量是否是浮点型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_int-function.html" title="is_int" rel="nofollow">is_int</a></td> 
   <td>检测变量是否是整数</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_int-function.html" title="is_integer" rel="nofollow">is_integer</a></td> 
   <td>is_int 的别名</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_iterable-function.html" title="is_iterable" rel="nofollow">is_iterable</a></td> 
   <td>检测变量的内容是否是一个可迭代的值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_int-function.html" title="is_long" rel="nofollow">is_long</a></td> 
   <td>is_int 的别名</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_null-function.html" title="is_null" rel="nofollow">is_null</a></td> 
   <td>检测变量是否为 NULL</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_numeric-function.html" title="is_numeric" rel="nofollow">is_numeric</a></td> 
   <td>检测变量是否为数字或数字字符串</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_object-function.html" title="is_object" rel="nofollow">is_object</a></td> 
   <td>检测变量是否是一个对象</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_float-function.html" title="is_real" rel="nofollow">is_real</a></td> 
   <td>is_float 的别名</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_resource-function.html" title="is_resource" rel="nofollow">is_resource</a></td> 
   <td>检测变量是否为资源类型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_scalar-function.html" title="is_scalar" rel="nofollow">is_scalar</a></td> 
   <td>检测变量是否是一个标量</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-is_string-function.html" title="is_string" rel="nofollow">is_string</a></td> 
   <td>检测变量是否是字符串</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-isset-function.html" title="isset" rel="nofollow">isset</a></td> 
   <td>检测变量是否已设置并且非 NULL</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-print_r-function.html" title="print_r" rel="nofollow">print_r</a></td> 
   <td>打印变量，输出易于阅读的信息。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-serialize-function.html" title="serialize" rel="nofollow">serialize</a></td> 
   <td>序列化对象</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-settype-function.html" title="settype" rel="nofollow">settype</a></td> 
   <td>设置变量的类型</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-strval-function.html" title="strval" rel="nofollow">strval</a></td> 
   <td>获取变量的字符串值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-unserialize-function.html" title="unserialize" rel="nofollow">unserialize</a></td> 
   <td>从已存储的表示中创建 PHP 的值</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-unset-function.html" title="unset" rel="nofollow">unset</a></td> 
   <td>释放给定的变量</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-var_dump-function.html" title="var_dump" rel="nofollow">var_dump</a></td> 
   <td>打印变量的相关信息</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-var_export-function.html" title="var_export" rel="nofollow">var_export</a></td> 
   <td>输出或返回一个变量，以字符串形式表示</td> 
  </tr> 
 </tbody> 
</table>

--------------------

### 密码散列算法 ###

<table> 
 <tbody> 
  <tr> 
   <th>函数</th> 
   <th>描述</th> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-password_get_info.html" title="password_get_info" rel="nofollow">password_get_info</a></td> 
   <td>返回指定散列（hash）的相关信息</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-password_hash.html" title="password_hash" rel="nofollow">password_hash</a></td> 
   <td>创建密码的散列（hash）</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-password_needs_rehash.html" title="password_needs_rehash" rel="nofollow">password_needs_rehash</a></td> 
   <td>检测散列值是否匹配指定的选项</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/php-password_verify.html" title="password_verify" rel="nofollow">password_verify</a></td> 
   <td>验证密码是否和散列值匹配</td> 
  </tr> 
 </tbody> 
</table>