PHP function overloading

Question

Coming from C   background    How can I overload PHP functions    One function definition if there are any arguments  and another if there are no arguments  Is it possible in PHP  Or should I use if else to check if there are any parameters passed from   GET and POST   and relate them

User · Answer

Sadly there is no overload in PHP as it is done in C   But i have a little trick  I declare arguments with default null values and check them in a function  That way my function can do different things depending on arguments  Below is simple example   public function query  queryString   class   null    second arg  is optional        query    this- gt dbLink- gt prepare  queryString        query- gt execute           if there is second argument method does different thing     if   is null  class               query- gt setFetchMode PDO  FETCH CLASS   class              return  query- gt fetchAll         This loads rows in to array of class  Result    this- gt query  queryString   SomeClass      This loads rows as standard arrays  Result    this- gt query  queryString

User · Answer

lt  php                                        author    hishamdalal gmail com     version   3 8    create on   2017-09-17    updated on   2020-01-12    download example   https   github com hishamdalal overloadable                                    gt  1  Include Overloadable class  class Overloadable       static function call  obj   method   params null             class   get class  obj              Get real method name          suffix method name    method self  getMethodSuffix  method   params            if  method exists  obj   suffix method name                    Call method             return call user func array array  obj   suffix method name    params            else              throw new Exception  Tried to call unknown method    class       suffix method name                        static function getMethodSuffix  method   params ary array               c                 if is array  params ary                foreach  params ary as  i  gt  param                      Adding special characters to the end of method name                  switch gettype  param                        case  array          c     a   break                      case  boolean        c     b   break                      case  double         c     d   break                      case  integer        c     i   break                      case  NULL           c     n   break                      case  object                              Support closure parameter                         if  param instanceof Closure                                 c     c                            else                               c     o                                                  break                      case  resource       c     r   break                      case  string         c     s   break                      case  unknown type   c     u   break                                                    return  c               Get a reference variable by name     static function  amp refAccess  var name             r   amp   GLOBALS  quot  var name quot             return  r            ----------------------------------------------------------   gt  2  create new class   ----------------------------------------------------------  class test        private  name    test-1          gt  3  Add   call  magic method  to your class         Call Overloadable class         you must copy this method in your class to activate overloading     function   call  method   args            return Overloadable  call  this   method   args                gt  4  Add your methods with    and arg type as one letter ie    i    s    is  and so on        gt  methodname  i   methodname  integer        gt  methodname  s   methodname  string        gt  methodname  is   methodname  integer   string          func void      function func               pre  func void      function                  func integer      function func  i  int            pre  func integer    int        function                  func string      function func  s  string            pre  func string    string        function                      func string  object      function func  so  string   object            pre  func string    string      print r  object  1         function               pre  object   Object                   func closure      function func  c Closure  callback                     pre  quot func  quot               print r                  array   callback   callback  this- gt name                      1                quot    quot     function     Closure                                       anotherFunction array      function anotherFunction  a  array            pre  anotherFunction   print r  array  1         function              array 0               change the reference value          array  val            change the reference value              anotherFunction string      function anotherFunction  s  key            pre  anotherFunction string    key        function                Get a reference          a2   amp  Overloadable  refAccess  key       a2   amp   GLOBALS  val             a2    3       change the reference value                 ----------------------------------------------------------    Some data to work with   val    10  class obj       private  x 10       ----------------------------------------------------------   gt  5  create your object     Start  t   new test     gt  6  Call your method     Call first method with no args   t- gt func        Output  func void    t- gt func  val      Output  func integer 10    t- gt func  quot hello quot       Output  func string hello    t- gt func  quot str quot   new obj        Output   func string str  obj Object        x obj private    gt  10            call method with closure function  t- gt func function  n       return strtoupper  n           Output  func Array        0    gt  Closure Object                        parameter    gt  Array                                         n    gt                                      1    gt  TEST-1             Passing by Reference   echo   lt br gt  lt br gt  val    val     Output   val 10   t- gt anotherFunction array  amp  val   val   gt  amp  val       Output  anotherFunction Array        0    gt  10      val    gt  10         echo  Result   val    val     Output   val 12   t- gt anotherFunction  val       Output  anotherFunction string val   echo  Result   val    val     Output   val 36           Helper function   ---------------------------------------------------------- function pre  mixed   title null        output    quot  lt fieldset gt  quot        output     title    quot  lt legend gt  lt h2 gt  title lt  h2 gt  lt  legend gt  quot     quot  quot        output      lt pre gt    print r  mixed  1     lt  pre gt         output     quot  lt  fieldset gt  quot       echo  output      ----------------------------------------------------------

User · Answer

It may be hackish to some  but I learned this way from how Cakephp does some functions and have adapted it because I like the flexibility it creates  The idea is you have different type of arguments  arrays  objects etc  then you detect what you were passed and go from there  function  arg1   lastname        if is array  arg1             lastname    arg1  lastname             firstname    arg1  firstname          else            firstname    arg1

User · Answer

In PHP 5 6 you can use the splat operator     as the last parameter and do away with func get args   and func num args     function example     args       count  args      Equivalent to func num args      example 1  2   example 1  2  3  4  5  6  7     You can use it to unpack arguments as well    args     1   args     2   args     3  example     args     Is equivalent to   example 1  2  3

User · Answer

PHP does not support overloading for now  Hope this will be implemented in the other versions like other programming languages   Checkout this library  This will allow you to use PHP Overloading in terms of closures  https   github com Sahil-Gulati Overloading

User · Answer

To over load a function simply do pass parameter as null by default   class ParentClass      function mymethod  arg1   null   arg2   null   arg3   null                     if   arg1    null  amp  amp   arg2    null  amp  amp   arg3    null                return  function has got zero parameters  lt br   gt                      else                       str                  if   arg1    null                   str     arg1      arg1    lt br   gt                if   arg2    null                   str     arg2      arg2    lt br   gt                if   arg3    null                   str     arg3      arg3    lt br   gt                return  str                          and call it in order given below        obj   new ParentClass    echo   lt br   gt  obj- gt mymethod   lt br   gt     echo  obj- gt mymethod      echo   lt br   gt  obj- gt mymethod null  test    lt br   gt     echo  obj- gt mymethod null  test      echo   lt br   gt   obj- gt mymethod  test   test   test   lt br   gt     echo  obj- gt mymethod  test   test   test

User · Answer

What about this   function  arg   NULL         if   arg    NULL            etc          etc

User · Answer

You cannot overload PHP functions  Function signatures are based only on their names and do not include argument lists  so you cannot have two functions with the same name  Class method overloading is different in PHP than in many other languages  PHP uses the same word but it describes a different pattern   You can  however  declare a variadic function that takes in a variable number of arguments  You would use func num args   and func get arg   to get the arguments passed  and use them normally   For example   function myFunc         for   i   0   i  lt  func num args     i              printf  Argument  d   s n    i  func get arg  i                Argument 0  a Argument 1  2 Argument 2  3 5    myFunc  a   2  3 5

User · Answer

lt  php      class abs               public function volume  arg1 null   arg2 null   arg3 null                           if  arg1    null  amp  amp   arg2    null  amp  amp   arg3    null                        echo  function has no arguments   lt br gt                       else if  arg1    null  amp  amp   arg2    null  amp  amp   arg3    null                             volume  arg1  arg2  arg3              echo  volume of a cuboid    volume    lt br gt                              else if  arg1    null  amp  amp   arg2    null                             area  arg1  arg2              echo  area of square        area    lt br gt                              else if  arg1    null                             volume  arg1  arg1  arg1               echo  volume of a cube      volume    lt br gt                                            obj new abs        echo  For no arguments   lt br gt         obj- gt volume        echo  For one arguments   lt br gt         obj- gt volume 3       echo  For two arguments   lt br gt         obj- gt volume 3 4       echo  For three arguments   lt br gt         obj- gt volume 3 4 5         gt

User · Answer

PHP doesn t support traditional method overloading  however one way you might be able to achieve what you want  would be to make use of the   call magic method   class MyClass       public function   call  name   args             switch   name                case  funcOne                   switch  count  args                         case 1                          return call user func array array  this   funcOneWithOneArg     args                       case 3                          return call user func array array  this   funcOneWithThreeArgs     args                                  case  anotherFunc                   switch  count  args                         case 0                          return  this- gt anotherFuncWithNoArgs                        case 5                          return call user func array array  this   anotherFuncWithMoreArgs     args                                          protected function funcOneWithOneArg  a                protected function funcOneWithThreeArgs  a   b   c                protected function anotherFuncWithNoArgs                 protected function anotherFuncWithMoreArgs  a   b   c   d   e

[php] PHP function overloading

Examples related to php

Examples related to arguments

Examples related to overloading