ReflectionClass::getParentClass()

(PHP 5, PHP 7)

获取父类

说明

publicReflectionClass::getParentClass(void): ReflectionClass

Warning

本函数还未编写文档，仅有参数列表。

参数

此函数没有参数。

返回值

一个ReflectionClass。

参见

• ReflectionClass::__construct() 初始化 ReflectionClass 类

Quick correction, the code for getting all parent classes below has a "typo", you need to reset the $class variable to the parent class instance, otherwise it just endlessly loops:
    $class = new ReflectionClass('classname');
    
    $parents = array();
    
    while ($parent = $class->getParentClass()) {
      $parents[] = $parent->getName();
      $class = $parent;
    }
    
    echo "Parents: " . implode(", ", $parents);

Here is a "replacement" for is_a that will additionally look both into the extended classes and in the implemented interfaces
<?php
/**
   * Check if a class extends or implements a specific class/interface
   * @param string $search The class or interface name to look for
   * @param string $className The class name of the object to compare to
   * @return bool
   */
  function IsExtendsOrImplements( $search, $className ) {
    $class = new ReflectionClass( $className );
    if( false === $class ) {
      return false;
    }
    do {
      $name = $class->getName();
      if( $search == $name ) {
        return true;
      }
      $interfaces = $class->getInterfaceNames();
      if( is_array( $interfaces ) && in_array( $search, $interfaces )) {
        return true;
      }
      $class = $class->getParentClass();
    } while( false !== $class );
    return false;
  }
?>

When you want to find all parents (parent, parent of parent, parent of parent's parent and so on) try:
<?php
$class = new ReflectionClass('whatever'); 
$parents = array();
while ($parent = $class->getParentClass()) {
  $parents[] = $parent->getName();
}
echo "Parents: " . implode(", ", $parents);
?>
ReflectionClass::getParentClass() can return a ReflectionClass object of the parent class or false if no parent.
(PHP Version 5.1.6)