LinkedIn PHP Skill Quiz Assessment Answers 2023

A PDO object called $db has been set up to use for database operations, including user authentication. All user-related properties are set. The script line public function __construct(&$db) shows a constructor that initializes all user-related properties to ____ if no user has logged in. These parameters will be properly set by the login functions when a user logs in.

1. NULL
2. TRUE
3. FALSE
4. 0

Correct Answer:

• NULL

All variables in PHP start with which symbol?

1. &
2. %
3. _
4. $

Correct Answer:

• $

Assuming that $first_name and $family_name are valid strings, which statement is invalid?

1. echo $first_name. ‘ ‘. $familiy_name;
2. print $first_name, ‘ ‘, $familiy_name;
3. print $first_name. ‘ ‘. $familiy_name;
4. echo $first_name, ‘ ‘, $familiy_name;

Correct Answer:

• print $first_name, ‘ ‘, $familiy_name;

Assuming the Horse class exists, which is a valid example of inheritance in PHP?

1. class Pegasus extends Horse {}
2. class Alicorn imports Pegasus, Unicorn {}
3. class Unicorn implements Horse {}
4. class Horse inherits Unicorn {}

Correct Answer:

• class Pegasus extends Horse {}

Both self and this are keywords that can be used to refer to member variables of an enclosing class. The difference is that $this->member should be used for __ members and self::$member should be used for __ members.

1. private, public
2. object,primitive
3. non-static,static
4. concrete,abstract

Correct Answer:

• non-static,static

Both triple === and double == can be used to **_ variables in php. If you want to hear that string “33” and the number 33 are equal, you would use ** . If you want to check if an array contains a particular string value at a particular index, you would use ___

1. compare; doubles;triples
2. compare; triples;doubles
3. assign; triples;doubles
4. assign;doubles;triples

Correct Answer:

• compare; doubles;triples

For the HTML form below, what is the correct functioning script that checks the input “mail” to be sure it is filled before proceeding?

if (!empty(\$\_POST[“mail”])) {
echo “Yes, mail is set”;
} else {
echo “No, mail is not set”;
} (correct)

How might you troubleshoot a “call to undefined function” error?

1. Make sure you have imported the file containing the function.
2. Make sure you have spelled the function name correctly.
3. all of these answers
4. Make sure the function declaration is at an earlier point in the code than the function call.

Correct Answer:

• all of these answers

In a conditional statement, you want to execute the code only if both value are true. Which comparison operator should you use?

1. ||
2. &
3. <=>
4. &&

Correct Answer:

• &&

In the following script, which line(s) will cause an error(s)?

1. Line 6 will cause an error because you can’t reassign a new value to a variable that has already been set.
2. Line 7 and 8 will cause an error. Line 7 has whitespace in $will i work and should be $will_i_work. Line 8 cannot start with a number befcause it is a variable.
3. Line 5 will cause an error because some_string should be someString.
4. Line 3 and 4 will cause an error because a variable cannot start with an underscore(_).

Correct Answer:

• Line 7 and 8 will cause an error. Line 7 has whitespace in $will i work and should be $will_i_work. Line 8 cannot start with a number befcause it is a variable.

PHP supports multiple types of loops. If you wanted to loop through a block of code if and as long a specified condition is true, which type of loop would you use?

1. for
2. do-while
3. while
4. foreach

Correct Answer:

• while

The **_ operator is useful for sorting operations. It compares two values and returns an integer less than, equal to, or greater than 0 depending on whether on whether the value on the _**is less than, equal to, or greater than the other.

1. greater-than; right
2. spaceship; left
3. equality; right
4. comparison; left

Correct Answer:

• spaceship; left

The PHP function array_reduce() takes a callback function that accepts a value carried over each iteration and the current item in the array, and reduces an array to a single value. Which code sample will sum and output the values in the provided array?

1. [ ]
   1 <?php
   2 echo array_reduce([1, 2, 5, 10, 11], function ($item, $carry) {
   3 $carry = $carry + \$item;
   4 });
   5?>
2. [ ]
   1 <?php
   2 echo array_reduce([1, 2, 5, 10, 11], function ($carry, $item) {
   3 return $carry = $item + \$item;
   4 });
   5?>
3. [ ]
   1 <?php
   2 array_reduce([11 2, 5, 10, 11], function ($item, $carry) {
   3 echo $carry + $item;
   4 });
   5?>
4. [X]
   1 <?php –CORRECT
   2 echo array_reduce([1, 2, 5, 10, 11], function ($carry, $item) {
   3 return $carry += $item;
   4 });
   5?>

Correct Answer:

• [x]
  1 <?php –CORRECT
  2 echo array_reduce([1, 2, 5, 10, 11], function ($carry, $item) {
  3 return $carry += $item;
  4 });
  5?>

The following XML document is in books.xml. Which code will output “Historical”?

1. $books = simplexml_load_string(‘books.xml’); echo $books->book[0]->categories->category[1];
2. $books = simplexml_load_file(‘books.xml’); echo $books->book[0]->categories->category[1];
3. $books = SimpleXMLElement(‘books.xml’); echo $books->book[0]->categories->category[1];
4. $books = SimpleXML(‘books.xml’); echo $books->book[0]->categories->category[1];

Correct Answer:

• $books = SimpleXMLElement(‘books.xml’); echo $books->book[0]->categories->category[1];

The ignore_user_abort( ) function sets whether a client disconnect should abort a script execution. In what scenario would you, as a web developer, use this function?

1. You would use it to stop a user from clicking the back button if they decide not to view as a result of a click. //Maybe
2. You would use this function if you have some important processing to do and you do not want to stop it, even if your users click Cancel.
3. You would use this function if you wanted to abort the script for all logged-in users, not just the one who disconnected.
4. You would use this function if you want a PHP script to run forever.

Correct Answer:

• You would use this function if you have some important processing to do and you do not want to stop it, even if your users click Cancel.

The php not operator is !. Given the snippet, is there an out put and what is it?

1. there is an output ‘2 is an even number
2. output ’21 is an odd number’
3. no output. Syntax error do to missing semicolon at the end
4. no output due to % in $num%2!=0

Correct Answer:

• output ’21 is an odd number’

What displays in a browser when the following code is written?

1. The browser would display nothing due to a syntax error.
2. The browser would display an error, since there are no parentheses around the string.
3. The browser would display How much are the bananas?
4. The browser would display an error, since there is no semicolon at the end of the echo command.

Correct Answer:

• The browser would display How much are the bananas?

What does this code output?

1. 1
2. -1
3. a parser error
4. 0

Correct Answer:

• a parser error

What does this script do?

1. It makes sure the email address is a good and functioning address
2. It makes an email safe to input into a database
3. It assigns an email to a variable and then removes all illegal characters from the $email variable
4. It verifies that an email address is well formed.

Correct Answer:

• It verifies that an email address is well formed.

What is a key difference between GET and POST?

1. GET is used with the HTTP protocol. POST is used with HTTPS.
2. GET displays the submitted data as part of the URL. During POST, this information is not shown, as it’s encoded in the request body.
3. GET is intended for changing the server state and it carries more data than POST.
4. GET is more secure than POST and should be used for sensitive information.

Correct Answer:

• GET displays the submitted data as part of the URL. During POST, this information is not shown, as it’s encoded in the request body.

What is missing from this code, which is supposed to create a test cookies?

1. The $_REQUEST is missing.
2. The $_COOKIES array is missing.
3. The cookie session is missing.
4. The call to setcookie() is missing.

Correct Answer:

• The call to setcookie() is missing.

What is the best way to explain what this script does?

1. This script times out the session for myusername.
2. Cookies are starting to be stored as a result of this script.
3. This script validates the username and password.
4. This script is on a page that requires the user to be logged in. It checks to see if the user has a valid session.

Correct Answer:

• This script is on a page that requires the user to be logged in. It checks to see if the user has a valid session.

What is the cause of ‘Cannot modify header information – headers already sent’?

1. You are trying to modify a private value
2. Semicolon missing
3. Using a key on an array that does not exists
4. Some html is being sent before a header() command that you are using for a redirect

Correct Answer:

• Some html is being sent before a header() command that you are using for a redirect

What is the job of the controller as a component in MVC?

1. The controller handles data passed to it by the view, and also passes data to the view. It interprets data sent by the view and disperses that data to the approrpiate models awaiting results to pass back to the view.
2. The controller is a mechanism that allows you to create reusable code in languages such as PHP, where multiple inheritance is not supported.
3. The controller presents content through the user interface, after communicating directly with the database.
4. The controller handles specific tasks related to a specific area of functionality, handles business logic related to the results, and communicates directly with the database.

Correct Answer:

• The controller handles specific tasks related to a specific area of functionality, handles business logic related to the results, and communicates directly with the database.

What is the purpose of adding a lowercase “u” as a modifier after the final delimiter in a Perl-compatible regular expression?

1. It makes the dot metacharacter match anything, including newline characters.
2. It makes the pattern match uppercase letters.
3. Both the pattern and subject string are treated as UTF-8.
4. It inverts the greediness of the quantifiers in the pattern so they are not greedy by default.

Correct Answer:

• Both the pattern and subject string are treated as UTF-8.

What is the significance of the three dots in this function signature?

1. It makes the function variadic, allowing it to accept as an argument an array containing an arbitrary number of values.
2. It makes the function variadic, allowing it to accept an arbitrary number of arguments that are converted into an array inside the function.
3. It temporarily disables the function while debugging other parts of the script.
4. It’s a placeholder like a TO DO reminder that automatically triggers a notice when you run a script before completing the function definition.

Correct Answer:

• It makes the function variadic, allowing it to accept an arbitrary number of arguments that are converted into an array inside the function.

What is the value of $total in this calculation?

1. 44
2. 138
3. 126
4. 100

Correct Answer:

• 100

What is the value of ‘$result’ in this calculation?

1. 4.167
2. 1.5
3. 4
4. 1

Correct Answer:

• 1

What will this code print?

LinkedIn PHP Skill Assessment Quiz Options:

1. euler3
2. hypatia5
3. hypatia3
4. fibonacci4

Correct Answer:

• hypatia3

LinkedIn Python Skill Assessment Quiz Options:

number = 3
print (f"The number is {number}")

1. The number is 3
2. the number is 3
3. THE NUMBER IS 3
4. It throws a TypeError because the integer must be cast to a string.

Correct Answer:

• The number is 3

Which PHP script uses a constructor to display the string “Winter is almost over!”?

1. 1 class MyClass {
   2 public function _construct()
   3 {
   4 echo 'Winter is almost over!'."\n";
   5 }
   6 }
   7 \$userclass = new MyClass;

2. 1 class MyClass {
   2 public function _construct()
   3 {
   4 echo 'Winter is almost over!.."\n";
   5 }
   6 }
   7 $userclass = new MyClass;

3. 1 class MyClass {
   2 public function _construct()
   3 {
   4 echo 'Winter is almost over!.."\n";
   5 }
   6 }
   7 \$userclass = new MyClass;

4. 1 class MyClass {
   2 public function _construct()
   3 {
   4 echo 'Winter is almost over!'."n";
   5 }
   6 }
   7 $userclass = MyClass;

Correct Answer:

• 1 class MyClass {
  2 public function _construct()
  3 {
  4 echo 'Winter is almost over!'."\n";
  5 }
  6 }
  7 \$userclass = new MyClass;

Which are valid PHP error handling keywords?

1. try, throw, catch, callable
2. try, yield, catch, finally
3. yield, throw, catch, finally
4. try, throw, catch, finally

Correct Answer:

• try, throw, catch, finally

Which code snippet demonstrates encapsulation?

1. [ ]
   class Cow extends Animal {
   private $milk;
   }
2. [ ]
   class Cow {
   public $milk;
   }
   $daisy = new Cow();
   $daisy->milk = “creamy”;
3. [ ]
   class Cow {
   public $milk;
   function getMilk() {`
   return $this->milk;
   }
   }
4. [x]
   class Cow {
   private $milk;
   public function getMilk() {
   return $this->milk;
   }
   }

Correct Answer:

• [x]
  class Cow {
  private $milk;
  public function getMilk() {
  return $this->milk;
  }
  }

Which code snippet uses the correct syntax for creating an instance of the Pet class?

1. $dog = new Pet;
2. all of these answers
3. $horse = (new Pet);
4. $cat = new Pet();

Correct Answer:

• all of these answers

Which code would you use to print all the elements in an array called $cupcakes?

1. all of the answers
2. print_r($cupcakes);
3. var_dump($cupcakes);
4. foreach($cupcakes as &$cupcake) echo $cupcake;

Correct Answer:

• all of the answers

Which is the correct format for adding a comment to a PHP script?

1. all of these answers
2. #This is a comment
3. /* This is a comment /
4. // This is a comment

Correct Answer:

• all of these answers

Which is the most secure way to avoid storing a password in clear text in database?

1. $encrypted = shal($password);
2. $encrypted = crypt($password, \$salt);
3. $encrypted = md5($password);
4. $encrypted = password_hash($password, PASSWORD_DEFAULT);

Correct Answer:

• $encrypted = password_hash($password, PASSWORD_DEFAULT);

Which is the way to create an array of “seasons”?

1. seasons=array( 1=>’spring’, 2=>’summer’, 3=>’autumn’, 4=>’winter’, );
2. $seasons=array(spring,summer,autumn,winter);
3. $seasons=(‘spring’,’summer’,’autumn’,’winter’);
4. $seasons=[‘spring’,’summer’,’autumn’,’winter’];

Correct Answer:

• $seasons=[‘spring’,’summer’,’autumn’,’winter’];

Which line could you NOT use to comment out “Space: the final frontier”?

1. /_ Space: the final frontier _/
2. / Space: the final frontier /
3. #Space: the final frontier
4. // Space: the final frontier

Correct Answer:

• / Space: the final frontier /

Which operator would you use to find the remainder after division?

1. /
2. %
3. //
4. DIV

Correct Answer:

• %

Which php control structure is used inside a loop to skip the rest of the current loops code and go back to the start of the loop for the next iteration

1. else
2. break
3. return
4. continue

Correct Answer:

• continue

Which value equates to true?

1. 0
2. NULL
3. ”
4. -1

Correct Answer:

• -1

Why does this code trigger an error? $string = ‘Shylock in a Shakespeare’s “Merchangt of Venice” demands his pound of flesh.’;

1. Strings should always be wrapped in double quotes; and double quotes inside a string should be escaped by backslashes.
2. All single and double quotes inside a string need to be escaped by backslashes to prevent a parse error.
3. The opening and closing single quotes should be replaced by double quotes; and the apostrophe should be escaped by a backslash.
4. The apostrophe needs to be escaped by a backslash to prevent it from being treated as the closing quote.

Correct Answer:

• The apostrophe needs to be escaped by a backslash to prevent it from being treated as the closing quote.

You are using the following code to find a users band, but it is returning false. Which step(s) would solve the problem?

1. check if fav_band is included in the query string at the top of your browser
2. all of the answers
3. view the source of form and make sure there is an input field with the name ‘fav_band’
4. print everything that has been transmitted in the request:print_r($_REQUEST);

Correct Answer:

• all of the answers

You want to list the modules available in your PHP installation. What command should you run?

1. php -h
2. php info
3. php -v
4. php -m

Correct Answer:

• php -m

Your php page is unexpectedly rendering as totally blank. Which step will shed light on the problem?

1. Add this code to the top of your script:ini_set(‘display_errors’,1);
2. check the server error logged
3. all of these answers
4. make sure you are not missing any semicolons

Correct Answer:

• all of these answers