Variable handling 函数
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is_object

(PHP 4, PHP 5)

is_object — 检测变量是否是一个对象

描述

bool is_object ( mixed $var )

如果 var 是一个 object 则返回 TRUE，否则返回 FALSE。

参见 is_bool()、is_int()、is_integer()、is_float()、is_string() 和 is_array()。

Variable handling 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 检测变量是否是一个对象

用户评论:

mark at not4you dot com (21-Sep-2011 08:23)

Unserializes data as returned by the standard PHP serialize() function. If the unserialized object is not an array, it will be converted to one, particularily useful if it returns a __PHP_Incomplete_Class.

<?php
/**
 *
 * @param string $data Serialized data
 *
 * @return array    Unserialized array
 */
function unserialize2array($data) {
    $obj = unserialize($data);
    if(is_array($obj)) return $obj;
    $arr = array();
    foreach($obj as $k=>$v) {
        $arr[$k] = $v;
    }
    unset($arr['__PHP_Incomplete_Class_Name']);
    return $arr;
}
?>

peter dot nagel at portavita dot nl (22-Mar-2011 09:46)

Note: is_object(null) returns false

This should actually be part of the input/output specification at the top of this page.

will (20-Mar-2010 10:36)

Just discovered:
is_a  (  object $object  ,  string $class_name  )
Which checks if the object is of this class or has this class as one of its parents

Which seems to do what a lot here are trying to replicate

ldean at saleamp dot com (01-Sep-2009 03:16)

Use instanceof() to check for a specific type.

Senthryl (17-Mar-2009 02:03)

Cleaning it up even more:

<?php
function is_obj(&$object, $className = null, $caseSensitive = true) {
    return is_object($object) && (!is_string($className) || preg_match('/^'.$className.'$/D'.($caseSensitive ? '' : 'i'), get_class($object)));
}
?>

gregdangelo at gmail dot com (14-Apr-2008 08:03)

cleaned up peter's code... use only one return statement

function is_obj( &$object, $check=null, $strict=true )
{
$result = false;
  if (is_object($object)) {
      if ($check == null) {
          $result =  true;
      } else {
           $object_name = get_class($object);
           $result =  ($strict === true)?
               ( $object_name == $check ):
               ( strtolower($object_name) == strtolower($check) );
      }  
  }
return $result;
}

peter at i-node dot com dot br (20-May-2006 09:03)

Optimizing the is_obj() from corychristison, and with the "return false" suggested by xixulon.

function is_obj( &$object, $check=null, $strict=true )
{
  if (is_object($object)) {
      if ($check == null) {
          return true;
      } else {
           $object_name = get_class($object);
           return ($strict === true)?
               ( $object_name == $check ):
               ( strtolower($object_name) == strtolower($check) );
      }   
  } else {
      return false;
  }
}

corychristison[aT-]lavacube(.dot)com (03-Feb-2005 01:06)

Thank you victor AT fourstones DOT net.

I have written a function to do what victor has suggested, with the ease of use of is_object. It can be used to replace is_object(), but has an extra field [$check], to compare to a certain name. If $check is left empty, it will just check if &$object is an object.

<?php

function is_obj( &$object, $check=null, $strict=true )
{
    if( $check == null && is_object($object) )
    {
        return true;
    }
    if( is_object($object) )
    {
        $object_name = get_class($object);
        if( $strict === true )
        {
            if( $object_name == $check )
            {
                return true;
            }
        }
        else
        {
            if( strtolower($object_name) == strtolower($check) )
            {
                return true;
            }
        }
    }
}

?>

This could probably be cleaned up, but it's spaced out to be easy to read.

victor AT fourstones DOT net (01-Jan-2005 11:49)

er, I don't think that's right, especially if calling from another object instance:

<?

function test_this()
{
    $c2 = new C2();
    $c2->func();
    $c1 = new C1();
    $c1->func();
    C1::func();
}

class C2
{
    function func()
    {
        C1::func();
    }
}

class C1
{
    function func()
    {
        if( isset($this) )
        {
            if( strtolower(get_class($this)) != 'c1' )
                print("oops\n");
            else
                print("this is ok\n" );
        }
        else
        {
            print("static call\n");
        }
    }
}

test_this();
?>

yields:
---------- run-php ----------

oops
this is ok
static call

corychristison[aT-]lavacube(.dot)com (01-Jan-2005 03:47)

You can use is_object($this) to detect if the function is being called via instance or procedure.

Example:

<?php

class mrClass {

    function test( )
    {
        if( is_object($this) )
        {
         // do something for instance method
            echo 'this is an instance call <br />' . "\n";
        }
        else
        {
         // do something different for procedural method
            echo 'this is a procedure call <br />' . "\n";
        }
    }

}

$inst = new mrClass();
$inst->test();

mrClass::test();

?>

This would output:
this is an instance call <br />
this is a procedure call <br />

:-) Happy coding!

lbjay can be emailed at reallywow dot com (02-May-2003 08:18)

I'm not even sure how to articulate this, so I'm going to just include test code. Maybe someone else will someday wonder the same thing.

<?
    error_reporting(E_ALL);
    class testParent
    {
        var $child;

        function testParent()
        {
            $this->child = new testChild();
        }
    }

    class testChild
    {
        function testChild()
        {
        }
    }

    $parent = new testParent();
    $parent2 = 'foobar';

    print join(',', Array(
        is_object($parent) ? 'yes' : 'no',
        is_object($parent->child) ? 'yes' : 'no',
        is_object($parent2) ? 'yes' : 'no',
        is_object($parent2->child) ? 'yes' : 'no'
    ));

?>

This prints "yes,yes,no,no". Basically this shows that you can use is_object to test if the child object is an object without worrying about an error if the parent object isn't an object either.