php prelim

Question 1

Which of the following represent a header for the mail() function?

Answer 1

“From: example@example.com”
“Subject: Important Message”

Question 2

Which two commands convert HTML tags to plain text?

Answer 2

html_entity_decode()
strip_tags()

Question 3

Which user-defined function sorts an array by keys?

Answer 3

ksort()

Question 4

What is the result of the command intdiv(9, 2)?

Answer 4

4
theres never a reminder and it rounds down

Question 5

What is the result ofthe following code: echo $today = date(“d/m/y”);?

Answer 5

“09/10/23”

Question 6

What are two effects of the sizeof(array) command?

Answer 6

Returns the number of elements in the array.
Returns the amount of memory (in bytes) used by the array

Question 7

What is the outcome of the given code snippet: $stack = array(“orange”, “banana”, “apple”,
“raspberry”); $fruit = array_pop($stack);?

Answer 7

$fruit = array_pop($stack); // $fruit contains “raspberry” and $stack is modified to [“orange”,
“banana”, “apple”]

Question 8

What is the proper sequence of steps to create an IF condition?

Answer 8

Condition, True Block, Optional Else Block.

Question 9

Which of the following are considered logically false values? (Choose 3)

Answer 9

false
null
0

Question 10

What is the purpose of IntlChar?

Answer 10

IntlChar is a PHP extension that provides functions to work with Unicode characters andstrings

Question 11

Which of the following represents a Null coalescing operator?

Answer 11

??

Question 12

What is the proper sequences of steps to establish a FOR condition?

Answer 12

Initialization, Condition, Increment/Decrement

Question 13

What is the outcome of the given code: $x = 0; do { echo “$x”; $x++; } while ($x != 10);?

Answer 13

The code will print numbers from 0 to 9

Question 14

Which three events terminate a session?

Answer 14

Closing the browser
Calling session_destroy()
Timeout due to inactivity

Question 15

Which PDO function safeguards against threats such as SQL injections?

Answer 15

PDO::prepare

Question 16

Which query retrieves the city and average age of cities with an average age greater than 30 years?

Answer 16

SELECT city, AVG(age) AS avg_age FROM citiesWHERE avg_age > 30

Question 16

Which of the following retrieves a value from a page indirectly?

Answer 16

$_SESSION

Question 17

What are two outcomes ofthe PDOStatement::fetchObjectstatement?

Answer 17

Retrieves the specified column values as object properties.
Fetches the next row from a result set as an object

Question 18

What are two effects of the session_destroy() function?

Answer 18

Ends the current session and closes the browser.
Deletes all data associated with the current session.

Question 19

What is the result of the following code? $sth = $dbh->prepare(“SELECT name, color FROM “fruit”);
@colcount = $sth->columnCount();

Answer 19

The code will generate a syntax error

Question 20

What is the result of the following code?
$auto = array (array(“Fiat”,24,13), array(“Ferrari”,45,33), array(“Jeep”,54,23), array(“Alfa
Romeo”,37,35));
for ($row = 3; $row < 4; $row++) {
for ($col = 0; $col < 3; $col++) {
echo $auto[$row][$col] . “-“;
}
}

Answer 20

“Alfa Romeo-37-35-“

Question 21

What does the memory_limit() parameter control in PHP?

Answer 21

The maximum amount of memory a PHP script can consume

Question 22

What is the primary distinction between MySQL and MariaDB?

Answer 22

MySQL is closed-source, while MariaDB is open-source.

Question 23

In which layer of the protocolstack is the acronym “www” typically found?

Answer 23

Application Layer

Question 24

Which two commands retrieve all data for reservations made by customers who live in Milan, where
Customers:=<Cod_cust, Surname,Name,Town, Salary, Age> and Reserv:=<Cod_cust, Cod_alb, Room,
Days, Account>

Answer 24

SELECT * FROM Reserv INNER JOIN Customers ON Reserv.Cod_cust =Customers.Cod_cust WHERE Customers.Town = ‘Milan’;

SELECT * FROM Reserv, Customers WHEREReserv.Cod_cust = Customers.Cod_cust AND Customers.Town = ‘Milan’;

Question 25

Which statement grants the user “user” full permissions for the “Display” database using the
password “1234”?

Answer 25

GRANT ALL PRIVILEGES ON Display TO ‘user’@’localhost’ IDENTIFIED BY ‘1234’;

Question 26

Which query returnsthe town and the maximum salary for each town that has an average age of less
than 35 years?

Answer 26

SELECT town, MAX(salary) FROM towns GROUP BY town HAVING AVG(age) < 35;

Question 27

Which query provides the town name and the number of customers from each town, sorted by the
number of customers?

Answer 27

SELECT town, COUNT(*) AS num_customers FROM customers GROUP BY town ORDER BY num_customers DESC;

Question 28

Which statement allows you to retrieve a list of all tables in a database?

Answer 28

SELECT * FROM information_schema.tables WHEREtable_schema = ‘your_database’;

Question 29

What is the outcome of the following code?
$fruits = array(“lemon”, “orange”, “banana”, “apple”); rsort($fruits);reset($fruits); while (list($ky,
$value) = each($fruits)) { echo “fruits[” . $key . “] = “ . $value . “\n”; }

Answer 29

It will display nothing.

Question 30

Which of the following indicates a comment?

Answer 30

(hashtagsymbol)This is a comment.

one only works in php and no other languages but the others also work in php

Question 31

What does the code $a % $b do?

Answer 31

Calculates the remainder when $a is divided by $b.

Question 32

What does the escape sequence \0 represent?

Answer 32

Null character ASCII
value zero

Question 33

Which two URLs enable the display of a dynamic page?

Answer 33

http://example.com/index.php
http://example.com/dynamic-page

Question 34

Which function can be used to check if a form field is incomplete?

Answer 34

empty()

Question 35

Which of the following retrieves a value from a URL?

Answer 35

$_GET

Question 36

Which two functions can be used to prevent SQL injection attacks?

Answer 36

mysqli_real_escape_string()
PDO::prepare()

Question 37

Which of the following are NOT allowed in a variable declaration?

Answer 37

Special characters like ! or @
Spaces
Keywords such as “if” or “else”

Question 38

In PHP, what is the purpose of the header() function, and how is it commonly used?

Answer 38

To send HTTP headers to the browser and control redirection.

Question 39

What does the term “SQL injection” refer to in the context of database security, and how can it be
prevented?

Answer 39

SQL injection is a vulnerability that allows attackers to manipulate SQL queries through userinputs.

Question 40

How can you connectto a MySQLdatabase using PHP, and what function is commonly used for this
purpose?

Answer 40

You can connect to a MySQL database using the mysqli_connect() function.

Question 41

What is the purpose of the mysqli_query() function in PHP when working with MySQL databases?

Answer 41

To execute SQLqueries on a MySQLdatabase.

Question 42

In PHP, how can you retrieve data from a form submitted using the POST method?

Answer 42

By using the $_POST superglobal array.

Question 43

Whatis the difference between mysqli and PDO when connecting to databases in PHP, and why might you choose one over the other?

Answer 43

mysqli is used for MySQL databases, while PDO supports multiple database types.

Question 44

In MySQL, what is a primary key, and why is it important in database design?

Answer 44

A primary key is a unique identifier for a table’s rows and ensures data integrity.

Question 45

How can you prevent SQL injection in PHP when processing user inputs in SQL queries?

Answer 45

By validating and escaping user inputs using functions like mysqli_real_escape_string().

Question 46

What does the PHP foreach loop do, and how is it commonly used?

Answer 46

The foreach loop iterates over elements in an array or other iterable objects

Question 47

What is the difference between mysql_ functions and mysqli_ functions in PHP when working with
MySQL databases?

Answer 47

mysqli_ functions are more modern and provide better security features and support for multiple statements and transactions.

Question 48

How can you create a new database in MySQL using PHP, and which SQL statement is commonly used for this purpose?

Answer 48

You can create anew database using the mysqli_query() function with the CREATEDATABASESQL statement.

Question 49

In PHP, what is the purpose of the implode() function, and how is it commonly used when working with arrays?

Answer 49

The implode() function is used to join array elements into a string