Online Quiz Attempt – Play & Test Your Knowledge

Question 1

1 / 10

Which of the following statements regarding PHP's garbage collection is most accurate?

PHP's garbage collection is disabled by default and must be manually enabled. PHP's garbage collection is a mark-and-sweep algorithm that primarily targets circular references. PHP's garbage collection is a reference counting system and automatically removes unreachable objects, even with circular references. PHP's garbage collection is executed only when the script terminates, regardless of memory usage.

Question 2

2 / 10

What is the primary purpose of the `__invoke()` magic method in PHP?

To overload the assignment operator for object properties. To automatically serialize an object when it is converted to a string. To allow an object to be called as a function. To intercept calls to undefined methods of a class.

Question 3

3 / 10

Consider the following code snippet: `function foo(?int $bar): int { return $bar ?? 0; }`. What happens if `foo(null)` is called?

A TypeError exception is thrown because null is not an int. The function returns 0. The function returns null. A warning is generated, but the function returns 0.

Question 4

4 / 10

Which of the following methods is LEAST effective for preventing SQL injection vulnerabilities in PHP?

Using prepared statements with parameterized queries. Escaping user input using `mysqli_real_escape_string()`. Whitelisting acceptable input values. Applying `strip_tags()` to all user input.

Question 5

5 / 10

What is the significance of the `yield from` keyword in PHP generators?

It allows a generator to return multiple values at once. It is used to define the type of value yielded by the generator. It delegates iteration to another iterable object or generator. It forces the generator to terminate execution prematurely.

Question 6

6 / 10

Which of the following statements regarding `SplObjectStorage` is most accurate?

It stores objects as keys and only allows integers as values. It stores objects as keys and allows any data type as values. It stores data as keys and only allows objects as values. It is a specialized array that optimizes object serialization.

Question 7

7 / 10

In PHP's trait system, what happens when a class uses multiple traits with methods of the same name and signature?

A fatal error is thrown, preventing the class from being defined. The method from the first trait listed in the `use` statement is used. The method from the last trait listed in the `use` statement is used. The class must resolve the conflict using the `insteadof` and `as` keywords.

Question 8

8 / 10

Which of the following is NOT a valid way to define a closure in PHP?

$func = function () {}; $func = create_function('', ''); $func = () => {}; $func = new Closure(function() {});

Question 9

9 / 10

What is the primary difference between `call_user_func()` and `call_user_func_array()` in PHP?

`call_user_func()` only accepts string function names, while `call_user_func_array()` can accept objects. `call_user_func()` accepts arguments individually, while `call_user_func_array()` accepts an array of arguments. `call_user_func()` is used for calling static methods, while `call_user_func_array()` is used for calling instance methods. There is no significant difference; they are interchangeable.

Question 10

10 / 10

Consider the following: `interface Foo { public function bar(): self; }`. What does the `self` return type hint indicate?

The `bar` method must return an object of a class that implements the `Foo` interface. The `bar` method must return an object of the same type as the class implementing the `Foo` interface. The `bar` method must return the current object instance (i.e., `$this`). The `bar` method can return any object type.

PHP Power Quiz