Quizzes – EduHub

Question 1

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

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

Question 2

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

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

Question 3

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

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

Question 4

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

SELECT INSERT DELETE UPDATE

Question 5

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

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

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

Question 8

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

GROUP BY WHERE HAVING ORDER BY

Question 9

Which jQuery method is used to hide an element?

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

Question 10

What does the `JOIN` clause in SQL do?

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

Question 11

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

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

Question 12

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

To set a default value for a column. To ensure unique values in 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?

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

Question 14

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

UPDATE DELETE FROM SELECT INSERT INTO

Question 15

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

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

Question 16

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

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

Question 17

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

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

Question 18

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

GROUP BY ORDER 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 set the current date and time. To automatically generate a unique sequential number for a column when a new row is inserted. 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?

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

Question 22

What is an `INNER JOIN` in SQL?

Returns all rows from the left table and matching rows from the right table. Returns only the rows where there is a match in both tables. 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.

Question 23

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

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

Question 24

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

CREATE TABLE CREATE DATABASE USE DATABASE ALTER DATABASE

Question 25

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

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

Question 26

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

INSERT INTO SELECT UPDATE DELETE FROM

Question 27

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

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

Question 28

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

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

Question 29

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

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

Question 30

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

UPDATE SELECT INSERT INTO DELETE FROM

Question 31

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

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

Question 32

In MySQL, what does `TRUNCATE TABLE` do?

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

Question 33

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

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

Question 34

What is a `LEFT JOIN` in SQL?

Returns rows that do not have a match in the other table. 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. Returns only rows where there is a match in both tables.

Question 35

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

.fadeIn() .hide() .animate() .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 HAVING WHERE GROUP BY

Question 37

Which jQuery method is used to create new DOM elements?

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

Question 38

What is a `UNION` operator in SQL?

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

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?

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

Question 41

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

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

Question 42

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

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

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

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?

DROP TABLE CREATE TABLE ALTER TABLE INSERT INTO

Question 47

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

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

Question 48

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

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

Question 49

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

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

Question 50

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

CREATE TABLE DROP TABLE DELETE FROM ALTER TABLE