Quizzes – EduHub

Question 1

Which jQuery method is used to select elements with a specific class name?

$("[attribute=value]") $(".className") $("#idName") $("tagName")

Question 2

In MySQL, what is the primary purpose of the `PRIMARY KEY` constraint?

To enforce a uniqueness constraint on a column, but not for row identification. To define a default value for a column. To ensure unique values in a column and to identify each row uniquely. To create a relationship between two tables.

Question 3

Which jQuery event handler is triggered when an input element's value changes and the element loses focus?

.submit() .change() .blur() .click()

Question 4

What is the SQL statement used to retrieve data from a database table?

UPDATE INSERT SELECT DELETE

Question 5

Which jQuery method is used to insert content at the end of selected elements?

.prepend() .before() .append() .after()

Question 6

In MySQL, which data type is most suitable for storing variable-length strings?

VARCHAR CHAR TEXT INT

Question 7

What does the `$(document).ready()` function in jQuery do?

It is used to handle form submissions. It executes code as soon as the DOM is ready, before external resources like images are loaded. It waits for a specific element to be ready before executing code. It executes code when the page is fully loaded, including images and other assets.

Question 8

Which MySQL clause is used to sort the result set of a query in ascending or descending order?

WHERE GROUP BY ORDER BY HAVING

Question 9

Which jQuery method is used to hide an element?

.fadeIn() .toggle() .hide() .show()

Question 10

What does the `JOIN` clause in SQL do?

It filters the results based on a condition. It removes duplicate rows from a result set. It combines rows from two or more tables based on a related column. It aggregates data from multiple rows.

Question 11

Which jQuery method is used to add a new class to an element?

.toggleClass() .addClass() .removeClass() .attr()

Question 12

In MySQL, what is the purpose of the `FOREIGN KEY` constraint?

To ensure unique values in a column. To set a default value for a column. To define a relationship between two tables, referencing the `PRIMARY KEY` of another table. To restrict values in a column to a specific set of options.

Question 13

What is the jQuery method for sending an asynchronous HTTP request?

.post() All of the above .get() .ajax()

Question 14

Which SQL statement is used to insert new records into a table?

UPDATE INSERT INTO DELETE FROM SELECT

Question 15

Which jQuery method is used to remove an element and its children?

.remove() .hide() .empty() .detach()

Question 16

In MySQL, what does the `DISTINCT` keyword do?

It counts the number of rows. It sorts the results in descending order. It limits the number of returned rows. It returns only unique values for a specified column.

Question 17

Which jQuery method is used to find the parent of a selected element?

.children() .parent() .closest() .siblings()

Question 18

Which SQL clause is used to filter rows based on aggregate function results?

ORDER BY GROUP BY WHERE HAVING

Question 19

Which jQuery method is used to get the content of an element?

.text() .attr() .html() .val()

Question 20

In MySQL, what is the purpose of the `AUTO_INCREMENT` property?

To automatically generate a unique sequential number for a column when a new row is inserted. To automatically set the current date and time. To ensure a column value is never null. To automatically update a column when it is changed.

Question 21

Which jQuery method is used to set or get the HTML content of an element?

.text() .val() .html() .attr()

Question 22

What is an `INNER JOIN` in SQL?

Returns all rows from the left table and matching rows from the right table. Returns rows that do not have a match in the other table. Returns all rows from both tables, with NULL values where there is no match. Returns only the rows where there is a match in both tables.

Question 23

Which jQuery selector is used to select elements based on their attribute?

$("tagName") $(".className") $("[attributeName]") $("#idName")

Question 24

In MySQL, which command is used to create a new database?

CREATE DATABASE ALTER DATABASE CREATE TABLE USE DATABASE

Question 25

Which jQuery method is used to add content to the end of each element in the set of matched elements?

.prepend() .append() .before() .after()

Question 26

What is the SQL statement used to modify existing records in a table?

SELECT UPDATE INSERT INTO DELETE FROM

Question 27

Which jQuery method is used to get the value of the first matched element?

.attr('value') .val() .text() .html()

Question 28

In MySQL, what is the purpose of the `INDEX` keyword?

To automatically generate sequential IDs. To improve the performance of data retrieval operations. To define relationships between tables. To enforce uniqueness on a column.

Question 29

Which jQuery method is used to iterate over a set of matched elements?

.map() .while() .for() .each()

Question 30

Which SQL statement is used to delete records from a table?

DELETE FROM UPDATE SELECT INSERT INTO

Question 31

Which jQuery method is used to filter elements based on a selector or function?

.find() .children() .parent() .filter()

Question 32

In MySQL, what does `TRUNCATE TABLE` do?

Deletes only specific rows based on a condition. Deletes all rows from a table, including the table structure. Removes duplicate rows from a table. Deletes all rows from a table, but keeps the table structure intact, and resets AUTO_INCREMENT values.

Question 33

Which jQuery method is used to add content to the beginning of each element in the set of matched elements?

.before() .prepend() .append() .after()

Question 34

What is a `LEFT JOIN` in SQL?

Returns rows that do not have a match in the other table. Returns only rows where there is a match in both tables. Returns all rows from the left table, and the matched rows from the right table. If there is no match, the result is NULL. Returns all rows from the right table, and the matched rows from the left table. If there is no match, the result is NULL.

Question 35

Which jQuery method is used to animate the opacity of an element?

.fadeIn() .animate() .hide() .slideDown()

Question 36

In MySQL, which clause is used with aggregate functions to group rows that have the same values in specified columns?

ORDER BY GROUP BY WHERE HAVING

Question 37

Which jQuery method is used to create new DOM elements?

$('<element>') $().append() $('selector') $().prepend()

Question 38

What is a `UNION` operator in SQL?

Combines rows from two or more SELECT statements, removing duplicates. Combines rows from two or more SELECT statements, including duplicates. Filters rows based on a condition. Merges columns from two tables.

Question 39

Which jQuery method is used to remove all child elements of the selected element?

.hide() .empty() .detach() .remove()

Question 40

In MySQL, what does the `ALTER TABLE` statement do?

Deletes an existing table. Creates a new table. Inserts data into a table. Modifies the structure of an existing table (e.g., adding, deleting, or modifying columns).

Question 41

Which jQuery method is used to attach an event handler to an element for the 'click' event?

.click(handler) .on('click', handler) .bind('click', handler) All of the above can be used in different contexts or older jQuery versions

Question 42

What is a `CASE` statement in SQL used for?

To handle errors during query execution. To perform conditional logic within a SQL statement, returning different values based on conditions. To define a new function within the database. To create a temporary table.

Question 43

Which jQuery method is used to find descendant elements of the selected element?

.children() .siblings() .find() .parent()

Question 44

In MySQL, what is the purpose of a `VIEW`?

To automatically generate reports. To enforce data integrity constraints. To physically store data in a separate table. To define a saved query that can be treated like a virtual table, simplifying data access.

Question 45

Which jQuery method is used to set or get attributes of elements?

.text() .attr() .html() .css()

Question 46

What is the SQL statement used to create a new table?

ALTER TABLE DROP TABLE CREATE TABLE INSERT INTO

Question 47

Which jQuery method is used to toggle the visibility of an element with a sliding effect?

.toggle() .animate() .fadeToggle() .slideToggle()

Question 48

In MySQL, what is a `JOIN` without a `WHERE` clause typically used for?

To sort the entire dataset. To calculate aggregate values. To retrieve all possible combinations of rows from the joined tables (a cross join). To filter out duplicate rows.

Question 49

Which jQuery method is used to trigger the 'click' event on selected elements?

.bind('click') .trigger('click') .on('click') .click(function(){})

Question 50

What is the SQL statement used to remove a table from the database?

ALTER TABLE DROP TABLE CREATE TABLE DELETE FROM