You are developing a web application where users can submit comments. Which of the following techniques would you implement to ensure that malicious scripts aren't executed when other users view the comments?
- Input Validation and Sanitization
- Server-Side Rendering (SSR)
- Using Base64 Encoding
- Implementing Captcha Verification
Input Validation and Sanitization are key to preventing Cross-Site Scripting (XSS) attacks. These techniques ensure that user input is thoroughly checked and sanitized to prevent the execution of malicious scripts when displaying comments. SSR, Base64 encoding, and Captcha are useful in other contexts but do not directly prevent XSS.
What is the main difference between a LEFT JOIN and a RIGHT JOIN in SQL?
- LEFT JOIN returns unmatched rows from the left table, RIGHT JOIN from the right table
- LEFT JOIN returns all rows from both tables, RIGHT JOIN only matching rows
- LEFT JOIN and RIGHT JOIN are the same, just synonyms for the same operation
- LEFT JOIN is used for numeric data, RIGHT JOIN for text data
The main difference between a LEFT JOIN and a RIGHT JOIN in SQL is that a LEFT JOIN returns all the rows from the left table and the matched rows from the right table, including unmatched rows from the left. In contrast, a RIGHT JOIN returns all the rows from the right table and the matched rows from the left table, including unmatched rows from the right.
The ________ function in PHP can be used to check if a certain function exists.
- function_exists()
- is_function()
- check_function()
- function_check()
The 'function_exists()' function in PHP checks if a certain function exists in the current script, which is useful for ensuring a function is available before calling it to prevent errors.
What is the purpose of the "return" statement in a PHP function?
- It outputs data to the browser.
- It ends the function's execution.
- It defines a variable.
- It declares a new function.
The "return" statement in a PHP function is used to end the function's execution and return a value or data to the calling code.
A(n) ________ token can be used to protect against CSRF attacks by ensuring that requests are genuine.
- Authentication
- Authorization
- CSRF
- Anti-CSRF
A "Anti-CSRF" token, also known as a CSRF token or synchronization token, is used to protect against CSRF (Cross-Site Request Forgery) attacks. It ensures that requests are genuine and originated from a trusted source.
If you want to sort an associative array by its values while maintaining key association, which function would you use?
- asort()
- sort()
- ksort()
- arsort()
The asort() function sorts an associative array by values while preserving key association, creating a new sorted array.
Input validation is essential for security, but relying solely on it can be dangerous because attackers can always find ways to ________ validation mechanisms.
- Bypass
- Enhance
- Invalidate
- Strengthen
Attackers can find ways to bypass validation mechanisms, making it crucial to implement additional security measures beyond validation.
Which PHP function is used to execute a MySQL query?
- mysql_execute
- mysqli_query
- mysql_query
- PDO::execute
The correct function is mysqli_query. It is used to execute a MySQL query in PHP using the MySQLi extension.
To handle exceptions in PHP, you should wrap the risky code within a ________ block.
- try
- catch
- throw
- finally
In PHP, you should wrap the risky code within a 'try' block. The 'try' block is used to enclose the code that may throw an exception.
In PHP, what is the difference between the '==' and '===' operators?
- '==' performs loose comparison
- '===' performs strict comparison
- '==' checks only value equality
- '===' checks value and type equality
'==' checks if the values are equal, while '===' checks both the values and data types. '===' is stricter and will return true only if both the value and data type match. '==' is more permissive.
Why is client-side validation alone not sufficient for securing form data?
- It cannot handle server errors
- It is easily bypassed by malicious users
- It slows down the form submission
- It is not compatible with modern browsers
Client-side validation can be easily bypassed, making it unreliable for security. It should be complemented with server-side validation to prevent malicious input.
What is the primary purpose of namespaces in PHP?
- Avoiding naming conflicts
- Grouping related functions
- Controlling access to functions
- Managing database connections
The primary purpose of namespaces in PHP is to avoid naming conflicts. It allows you to create distinct, isolated spaces for your code, preventing naming clashes in large projects.