What is stdClass in PHP

Question

Please define what stdClass is

User · Answer

If you wanted to quickly create a new object to hold some data about a book. You would do something like this:

$book = new stdClass;
$book->title = "Harry Potter and the Prisoner of Azkaban";
$book->author = "J. K. Rowling";
$book->publisher = "Arthur A. Levine Books";
$book->amazon_link = "http://www.amazon.com/dp/0439136369/";

Please check the site - http://www.webmaster-source.com/2009/08/20/php-stdclass-storing-data-object-instead-array/ for more details.

User · Answer

stdClass is just a generic  empty  class that s used when casting other types to objects  Despite what the other two answers say  stdClass is not the base class for objects in PHP   This can be demonstrated fairly easily   class Foo    foo   new Foo    echo   foo instanceof stdClass   Y   N      outputs  N    I don t believe there s a concept of a base object in PHP

User · Answer

php net manual has a few solid explanation and examples contributed by users of what stdClass is  I especially like this one http   php net manual en language oop5 basic php 92123  https   stackoverflow com a 1434375 2352773      stdClass is the default PHP object  stdClass has no properties    methods or parent  It does not support magic methods  and implements   no interfaces       When you cast a scalar or array as Object  you get an instance of   stdClass  You can use stdClass whenever you need a generic object   instance       stdClass is NOT a base class  PHP classes do not automatically inherit   from any class  All classes are standalone  unless they explicitly   extend another class  PHP differs from many object-oriented languages   in this respect       You could define a class that extends stdClass  but you would get no   benefit  as stdClass does nothing

User · Answer

stClass is an empty class created by php itself   and should be used by php only  because it is not just an  empty  class    php uses stdClass to convert arrays to object style if you need to use stdClass   I recommend two better options    1- use arrays  much faster than classes   2- make your own empty class and use it    example 1  data array  k1   gt  v1     k2   gt  v2            example 2   creating an empty class is faster than instances an stdClass class data     data new data     data- gt k1  v1    data- gt k2  v2     what makes someone to think about using the object style instead of array style

User · Answer

The reason why we have stdClass is because in PHP there is no way to distinguish a normal array from an associate array  like in Javascript you have    for object and    for array to distinguish them    So this creates a problem for empty objects  Take this for example   PHP    a    1  2  3      this is an array  b     one    gt  1   two    gt  2      this is an associate array  aka hash   c     a    gt   a   b    gt   b      this is also an associate array  aka hash    Let s assume you want to JSON encode the variable  c  echo json encode  c      outputs   gt    a    1 2 3    b    one  1  two  2     Now let s say you deleted all the keys from  b making it empty  Since  b is now empty  you deleted all the keys remember    it looks like    which can be either an array or object if you look at it   So if you do a json encode again  the output will be different  echo json encode  c      outputs   gt    a    1 2 3    b         This is a problem because we know b that was supposed to be an associate array but PHP  or any function like json encode  doesn t   So stdClass comes to rescue  Taking the same example again   a    1  2  3      this is an array  b    object    one    gt  1   two    gt  2      this makes it an stdClass  c     a    gt   a   b    gt   b      this is also an associate array  aka hash    So now even if you delete all keys from  b and make it empty  since it is an stdClass it won t matter and when you json encode it you will get this   echo json encode  c      outputs   gt    a    1 2 3    b         This is also the reason why json encode and json decode by default return stdClass      c   json decode    a    1 2 3    b         true     true to deocde as array      c is now   a    gt   1 2 3    b    gt      in PHP     if you json encode  c  again your data is now corrupted

User · Answer

stdClass objects in use  The stdClass allows you to create anonymous classes and with object casting you can also access keys of an associative array in OOP style  Just like you would access the regular object property    Example   class Example      private  options     public function   construct Array  setup             casting Array to stdClass object      this- gt options    object   setup          access stdClass object in oop style - here transform data in OOP style using some custom method or something        echo  this- gt options- gt   name       - gt   key       echo  this- gt options- gt surname      - gt key          ob1   new Example   name    gt   John    surname    gt   Doe       will echo     John Doe

User · Answer

stdClass is a another great PHP feature  You can create a anonymous PHP class  Lets check an example    page new stdClass     page- gt name  Home    page- gt status 1    now think you have a another class that will initialize with a page object and execute base on it    lt  php class PageShow        public  currentpage       public function   construct  pageobj                 this- gt currentpage    pageobj             public function show                 echo  this- gt currentpage- gt name           state     this- gt currentpage- gt status    1     Active     Inactive           echo  This is      state     page             Now you have to create a new PageShow object with a Page Object    Here no need to write a new Class Template for this you can simply use stdClass to create a Class on the fly        pageview new PageShow  page        pageview- gt show

User · Answer

stdClass is not an anonymous class or anonymous object Answers here includes expressions that stdClass is an anonymous class or even anonymous object  It s not a true  stdClass is just a regular predefined class  You can check this using instanceof operator or function get class  Nothing special goes here  PHP uses this class when casting other values to object  In many cases where stdClass is used by the programmers the array is better option  because of useful functions and the fact that this usecase represents the data structure not a real object

User · Answer

stdClass is PHP s generic empty class  kind of like Object in Java or object in Python  Edit  but not actually used as universal base class  thanks  Ciaran for pointing this out    It is useful for anonymous objects  dynamic properties  etc    An easy way to consider the StdClass is as an alternative to associative array  See this example below that shows how json decode   allows to get an StdClass instance or an associative array  Also but not shown in this example  SoapClient    soapCall returns an StdClass instance    lt  php   Example with StdClass  json       foo    bar    number   42      stdInstance   json decode  json   echo  stdInstance- gt foo   PHP EOL     bar  echo  stdInstance- gt number   PHP EOL    42   Example with associative array  array   json decode  json  true   echo  array  foo     PHP EOL     bar  echo  array  number     PHP EOL    42   See Dynamic Properties in PHP and StdClass for more examples

User · Answer

Actually I tried creating empty stdClass and compared the speed to empty class   class emp     then proceeded creating 1000 stdClasses and emps    empty classes were done in around 1100 microseconds while stdClasses took over 1700 microseconds  So I guess its better to create your own dummy class for storing data if you want to use objects for that so badly  arrays are a lot faster for both writing and reading

User · Answer

Likewise     myNewObj- gt setNewVar    newVal      yields a stdClass object - auto casted  I found this out today by misspelling    GLOBASLS  myObj  - gt myPropertyObj- gt myProperty    myVal     Cool

User · Answer

You can also use object to cast arrays to an object of your choice   Class Example      public  name     public  age      Now to create an object of type Example and to initialize it you can do either of these    example   new Example     example- gt name    some name    example- gt age   22    OR   example   new Example     example    object    name    gt   some name    age    gt  22     The second method is mostly useful for initializing objects with many properties

User · Answer

stdclass is a way in which the php avoid stopping interpreting the script when there is some data must be put in a class   but  unfortunately this class was  not defined  Example      return  statement- gt fetchAll PDO  FETCH CLASS     Tasks      Here the data will be put in the predefined  Tasks    But  if we did the code as this     return  statement- gt fetchAll PDO  FETCH CLASS      then the php will put the results in stdclass    simply php says that   look   we have a good KIDS Objects  Here but without Parents   So   we will send them to a infant child Care Home stdclass

User · Answer

Using stdClass you can create a new object with it s own properties  Consider the following example that represents the details of a user as an associative array    array user   array     array user  name      smith john    array user  username      smith    array user  id      1002    array user  email      smith nomail com     If you need to represent the same details as the properties of an object  you can use stdClass as below    obj user   new stdClass   obj user- gt name    smith john    obj user- gt username    smith    obj user- gt id    1002    obj user- gt email    smith nomail com     If you are a Joomla developer refer this example in the Joomla docs for further understanding

User · Answer

Its also worth noting that by using Casting you do not actually need to create an object as in the answer given by  Bandula  Instead you can simply cast your array to an object and the stdClass is returned  For example    array   array       Property1   gt  hello        Property2   gt  world        Property3   gt  again        obj    object   array  echo  obj- gt Property3    Output  again

User · Answer

Please bear in mind that 2 empty stdClasses are not strictly equal  This is very important when writing mockery expectations   php  gt   a   new stdClass    php  gt   b   new stdClass    php  gt  var dump  a      b   bool false  php  gt  var dump  a     b   bool true  php  gt  var dump  a   object stdClass  1  0      php  gt  var dump  b   object stdClass  2  0      php  gt

User · Answer

Also worth noting  an stdClass object can be created from the use of json decode   as well

[php] What is stdClass in PHP?

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