Contents
- 1 1. What is PHP, and what does it stand for?
- 2 2. How do you comment out code in PHP?
- 3 3. What is the difference between == and === in PHP for comparison?
- 4 4. How do you declare a variable in PHP?
- 5 5. Explain the purpose of the $_GET and $_POST superglobal arrays in PHP.
- 6 6. What is the difference between include and require in PHP for file inclusion?
- 7 7. How do you connect to a MySQL database in PHP?
- 8 8. What is the purpose of the session_start() function in PHP?
- 9 9. Explain what SQL injection is and how to prevent it in PHP.
- 10 10. How do you send email using PHP?
- 11 Related Some more Details:
1. What is PHP, and what does it stand for?
Answer: PHP stands for “Hypertext Preprocessor.” It is a server-side scripting language primarily used for web development to create dynamic web pages. PHP code is embedded within HTML to generate content dynamically.
2. How do you comment out code in PHP?
Answer: In PHP, you can use //
for single-line comments and /* */
for multi-line comments. For example:
3. What is the difference between ==
and ===
in PHP for comparison?
Answer:
==
is a loose comparison operator that checks if the values of two variables are equal, even if their data types are different (type coercion).===
is a strict comparison operator that checks if the values and data types of two variables are identical.
4. How do you declare a variable in PHP?
Answer: Variables in PHP start with a dollar sign $
, followed by the variable name. For example:
5. Explain the purpose of the $_GET
and $_POST
superglobal arrays in PHP.
Answer:
$_GET
is an associative array that holds data sent to the server via URL parameters (query string) in an HTTP GET request.$_POST
is an associative array that holds data sent to the server via the HTTP POST method, typically used for form submissions.
6. What is the difference between include
and require
in PHP for file inclusion?
Answer:
include
includes a file and generates a warning if the file is not found, allowing the script to continue executing.require
includes a file but generates a fatal error if the file is not found, halting script execution.
7. How do you connect to a MySQL database in PHP?
Answer: You can use the mysqli
or PDO
extension to connect to a MySQL database in PHP. Here’s an example using mysqli
8. What is the purpose of the session_start()
function in PHP?
Answer: session_start()
is used to start or resume a user’s session in PHP. It initializes a session or resumes the existing session if one is available. Sessions are used to store user-specific data across multiple pages or requests.
9. Explain what SQL injection is and how to prevent it in PHP.
Answer: SQL injection is a security vulnerability where malicious SQL statements are inserted into user inputs and executed by a database. To prevent SQL injection in PHP, use prepared statements and parameterized queries provided by mysqli
or PDO
. These methods sanitize and validate user inputs before interacting with the database.