Question

I have a custom PHP class with few methods in it. Is is possible to call class method this way:

<?php 
class someClass{
  function someMethod_somename_1(){
    echo 'somename1';       
  }

  function someMethod_somename_2(){
    echo 'somename2';   
  }
}
$obj = new someClass();
$methodName = $_GET['method_name'];
$obj->someMethod_{$methodName}(); //calling method
?>

My real world application is more complex, but here I provide just this simple example to get the main idea. Maybe I can use eval function here?

Answer 1

Please don’t use eval() because it’s evil in most situations.

Simple string concatenation helps you:

$obj->{'someMethod_'.$methodName}();

You should also verify the user input!

$allowedMethodNames = array('someone_2', 'someone_1');
if (!in_array($methodName, $allowedMethodNames)) {
  // ERROR!
}

// Unrestricted access but don't call a non-existing method!
$reflClass = new ReflectionClass($obj);
if (!in_array('someMethod_'.$methodName, $reflClass->getMethods())) {
  // ERROR!
}

// You can also do this
$reflClass = new ReflectionClass($obj);
try {
  $reflClass->getMethod('someMethod_'.$methodName);
}
catch (ReflectionException $e) {
  // ERROR!
}

// You can also do this as others have mentioned
call_user_func(array($obj, 'someMethod_'.$methodName));