__call and __callStatic in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the magic method that handles calls to undefined instance methods.

PHP

<?php
class Test {
    public function [1]($name, $arguments) {
        echo "Called method: $name";
    }
}
$test = new Test();
$test->hello();

Drag options to blanks, or click blank then click option'

A__get

B__callStatic

C__set

D__call

Attempts:

3 left

💡 Hint

Common Mistakes

Using __callStatic instead of __call for instance methods.

Confusing __call with property access magic methods like __get or __set.

The __call method is triggered when invoking inaccessible or undefined instance methods.

2fill in blank

medium

Complete the code to define the magic method that handles calls to undefined static methods.

PHP

<?php
class Test {
    public static function [1]($name, $arguments) {
        echo "Called static method: $name";
    }
}
Test::hello();

Drag options to blanks, or click blank then click option'

A__call

B__destruct

C__callStatic

D__invoke

Attempts:

3 left

💡 Hint

Common Mistakes

Using __call instead of __callStatic for static methods.

Confusing __callStatic with other magic methods like __invoke.

The __callStatic method is triggered when invoking inaccessible or undefined static methods.

3fill in blank

hard

Fix the error in the code by completing the magic method name that handles undefined instance method calls.

PHP

<?php
class Demo {
    public function [1]($method, $args) {
        echo "Method $method called with arguments: " . implode(', ', $args);
    }
}
$obj = new Demo();
$obj->test(1, 2);

Drag options to blanks, or click blank then click option'

A__call

B__callStatic

C__get

D__set

Attempts:

3 left

💡 Hint

Common Mistakes

Using __callStatic instead of __call for instance methods.

Forgetting the method must be public.

The magic method __call handles calls to undefined instance methods, receiving the method name and arguments.

4fill in blank

hard

Fill both blanks to complete the class that handles undefined instance and static method calls.

PHP

<?php
class Magic {
    public function [1]($name, $args) {
        echo "Instance method $name called.";
    }
    public static function [2]($name, $args) {
        echo "Static method $name called.";
    }
}
Magic::foo();
$magic = new Magic();
$magic->bar();

Drag options to blanks, or click blank then click option'

A__call

B__invoke

C__callStatic

D__get

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up __call and __callStatic.

Not declaring __callStatic as static.

__call handles undefined instance methods, and __callStatic handles undefined static methods.

5fill in blank

hard

Fill all three blanks to create a class that logs calls to undefined instance and static methods with method names and arguments.

PHP

<?php
class Logger {
    public function [1]($name, $args) {
        echo "Instance call: $name with args: " . implode(', ', $[2]) . "\n";
    }
    public static function [3]($name, $args) {
        echo "Static call: $name with args: " . implode(', ', $args) . "\n";
    }
}
$log = new Logger();
$log->run(5, 10);
Logger::start('a', 'b');

Drag options to blanks, or click blank then click option'

A__call

Bargs

C__callStatic

Darguments

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable name for arguments.

Confusing __call and __callStatic.

Not declaring __callStatic as static.

The __call method handles instance calls, using the args parameter for arguments. The __callStatic method handles static calls.

Practice

1. What is the main purpose of the __call magic method in PHP?

easy

A. To automatically serialize objects

B. To handle calls to undefined static methods

C. To handle calls to undefined instance methods

D. To overload operators like + and -

Solution

1. Step 1: Understand the role of __call

   The __call method is triggered when an undefined instance method is called on an object.

2. Step 2: Differentiate from __callStatic

   __callStatic handles undefined static method calls, not instance calls.

3. Final Answer:

   To handle calls to undefined instance methods -> Option C

4. Quick Check:

   __call = instance method handler [OK]

Hint: Instance missing methods use __call, static ones use __callStatic [OK]

Common Mistakes:

• Confusing __call with __callStatic
• Thinking __call handles static methods
• Assuming __call serializes objects

2. Which of the following is the correct syntax to declare the __callStatic method in a PHP class?

easy

A. public static function __callStatic($name, $arguments)

B. public function __callStatic($name, $arguments)

C. static function __callStatic($name, $arguments)

D. function __callStatic($name, $arguments)

Solution

1. Step 1: Recall method declaration rules for static magic methods

   The __callStatic method must be declared as public static function to handle static calls.

2. Step 2: Check each option's syntax

   public static function __callStatic($name, $arguments) correctly uses public static function. Options B and D miss static, and C misses public.

3. Final Answer:

   public static function __callStatic($name, $arguments) -> Option A

4. Quick Check:

   Static magic methods need 'public static' [OK]

Hint: Static magic methods need 'public static' keyword [OK]

Common Mistakes:

• Omitting 'static' keyword
• Omitting 'public' visibility
• Using wrong parameter names

3. What will be the output of the following PHP code?

class Test {
    public function __call($name, $args) {
        echo "Called method: $name with argument: " . $args[0];
    }
}

$obj = new Test();
$obj->hello('world');

medium

A. Called method: hello with argument: world

B. Fatal error: Call to undefined method Test::hello()

C. Called method: __call with argument: world

D. No output

Solution

1. Step 1: Identify method call and class behavior

   The method hello is not defined in Test, so __call is triggered.

2. Step 2: Understand __call output

   __call echoes the method name and first argument, so it prints "Called method: hello with argument: world".

3. Final Answer:

   Called method: hello with argument: world -> Option A

4. Quick Check:

   Undefined instance method triggers __call [OK]

Hint: Undefined instance calls trigger __call with method name [OK]

Common Mistakes:

• Expecting fatal error instead of __call handling
• Confusing __call with __callStatic
• Ignoring argument array usage

4. Consider this PHP code snippet:

class Demo {
    public static function __callStatic($name, $args) {
        echo "Static call to $name";
    }
}

Demo::test();

What is the error in this code?

medium

A. Missing public keyword in __callStatic declaration

B. Cannot call static method __callStatic directly

C. Class Demo must define __call method for static calls

D. No error; code runs and prints 'Static call to test'

Solution

1. Step 1: Check method declaration and call

   __callStatic is declared correctly as public static function and is called via Demo::test().

2. Step 2: Understand magic method behavior

   Since test is undefined static method, __callStatic is triggered and echoes the message.

3. Final Answer:

   No error; code runs and prints 'Static call to test' -> Option D

4. Quick Check:

   Undefined static calls trigger __callStatic [OK]

Hint: Undefined static calls invoke __callStatic automatically [OK]

Common Mistakes:

• Thinking __call is needed for static calls
• Assuming direct call to __callStatic is required
• Missing 'public' or 'static' keywords

5. You want to create a PHP class that logs every call to undefined instance or static methods with their names and arguments. Which approach correctly uses __call and __callStatic to achieve this?

hard

A. Use normal methods with logging inside; magic methods cannot log undefined calls

B. Implement __call for instance methods and __callStatic for static methods, both logging method name and args

C. Implement only __callStatic to catch all method calls, static and instance

D. Implement only __call to catch all method calls, static and instance

Solution

1. Step 1: Understand magic methods roles

   __call handles undefined instance method calls; __callStatic handles undefined static method calls.

2. Step 2: Combine both for full coverage

   To log all undefined calls, implement both methods to log method names and arguments accordingly.

3. Final Answer:

   Implement __call for instance methods and __callStatic for static methods, both logging method name and args -> Option B

4. Quick Check:

   Use both __call and __callStatic for full logging [OK]

Hint: Use both __call and __callStatic to catch all undefined calls [OK]

Common Mistakes:

• Using only one magic method for both call types
• Thinking magic methods cannot log calls
• Confusing instance and static method handling