Short overview on Unit-IV

 

📘 Unit–IV: User Data Input through Forms

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4a. Steps to Create an Input Form

👉 A form is used to collect input from users and send it to a server for processing.

Steps

1. Use <form> tag in HTML to create the form.

2. Define action (where the form data will go) and method (how the data will be sent → GET/POST).

3. Add input fields (text, email, password, radio, checkbox, etc.).

4. Add a submit button.

5. Process the data in a PHP file.

Example

<!-- form.html -->
<form action="process.php" method="post">
  Name: <input type="text" name="uname"><br>
  Email: <input type="email" name="uemail"><br>
  <input type="submit" value="Submit">
</form>

<!-- process.php -->
<?php
$name = $_POST['uname'];
$email = $_POST['uemail'];
echo "Welcome $name, your email is $email";
?>

📌 Diagram:
[User] → [Form Input] → [Submit] → [Server (PHP)] → [Output Display]

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4b. Steps to Use PHP Super Global Methods

PHP provides superglobals ($_GET, $_POST, $_REQUEST) to collect data.

Steps

1. Create a form with method="get" or method="post".

2. Use respective superglobal in PHP to fetch data.

3. Process and display the result.

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Example with GET

<form action="getdata.php" method="get">
  Enter Age: <input type="number" name="age">
  <input type="submit" value="Submit">
</form>

<!-- getdata.php -->
<?php
echo "Your age is " . $_GET['age'];
?>

📌 Data appears in URL → getdata.php?age=20

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Example with POST

<form action="postdata.php" method="post">
  Password: <input type="password" name="pass">
  <input type="submit" value="Login">
</form>

<!-- postdata.php -->
<?php
echo "Your password is " . $_POST['pass'];
?>

📌 Data is not shown in URL (more secure).

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Example with REQUEST

<?php
echo "Name: " . $_REQUEST['uname'];
?>

📌 $_REQUEST can handle both GET and POST.

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4c. Steps to Create and Manage Sessions

👉 A session stores user data across multiple pages (unlike variables which are lost when page refreshes).

Steps

1. Start a session using session_start(); at the top of PHP file.

2. Store session variables using $_SESSION['key'].

3. Access session variables on other pages.

4. Destroy session when user logs out.

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Example

<!-- page1.php -->
<?php
session_start();
$_SESSION['username'] = "Jaydeep";
echo "Session started!";
?>

<!-- page2.php -->
<?php
session_start();
echo "Welcome " . $_SESSION['username'];
?>

<!-- logout.php -->
<?php
session_start();
session_destroy();
echo "Session destroyed, user logged out!";
?>

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Summary Table

Feature	Method	Use Case	Visibility
$_GET	GET	Small data, search queries	Visible in URL
$_POST	POST	Login forms, passwords	Hidden from URL
$_REQUEST	GET+POST	General purpose	Depends on method
SESSION	Server-side	Login, shopping cart	Secure, persists

Part–1: MCQs (15 Questions)

Q1. Which HTML tag is used to create a form?
a) <input>
b) <form> ✅
c) <action>
d) <data>

Q2. Which attribute of <form> defines the method used to send data?
a) type
b) action
c) method ✅
d) submit

Q3. Which superglobal is used to collect form data sent using POST method?
a) $_POST ✅
b) $_GET
c) $_REQUEST
d) $_SESSION

Q4. Data submitted through GET method is visible in:
a) Session
b) URL ✅
c) Database
d) Cookies

Q5. Which method is more secure for password submission?
a) GET
b) POST ✅
c) REQUEST
d) SESSION

Q6. What function is used to start a PHP session?
a) start_session()
b) begin_session()
c) session_start() ✅
d) session_open()

Q7. Which of the following is NOT a superglobal variable in PHP?
a) $_POST
b) $_DATA ✅
c) $_REQUEST
d) $_SESSION

Q8. Which PHP superglobal can handle both GET and POST data?
a) $_DATA
b) $_REQUEST ✅
c) $_SESSION
d) $_FORM

Q9. Which function is used to destroy a session in PHP?
a) end_session()
b) destroy_session()
c) session_destroy() ✅
d) exit_session()

Q10. What is the default method of a form if not specified?
a) GET ✅
b) POST
c) REQUEST
d) SESSION

Q11. Which superglobal is used to store session variables?
a) $_DATA
b) $_SESSION ✅
c) $_GLOBAL
d) $_POST

Q12. Which input type is used to create a password field?
a) text
b) hidden
c) password ✅
d) email

Q13. Which form method should be used for sensitive information?
a) GET
b) POST ✅
c) REQUEST
d) SESSION

Q14. Which PHP superglobal stores cookie values?
a) $_COOKIE ✅
b) $_POST
c) $_SESSION
d) $_GLOBALS

Q15. Which diagram represents user input flow correctly?
a) Form → Server → Output ✅
b) Server → Form → Output
c) Database → Form → Server
d) Output → Form → Server

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✅ Part–2: Descriptive Q&A (3–4 Marks Each)

Q1. Define PHP forms. Explain the steps to create an input form.
Answer:
A PHP form is used to collect user data and send it to the server for processing.
Steps:

1. Use <form> tag with action and method.

2. Add input fields (text, password, email, etc.).

3. Add a submit button.

4. Process form data using PHP ($_GET / $_POST).

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Q2. Differentiate between GET and POST methods.
Answer:

• GET: Sends data through the URL, suitable for small data, not secure.

• POST: Sends data in the request body, hidden from URL, secure for sensitive data like passwords.

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Q3. What is the use of PHP superglobals?
Answer:
Superglobals are built-in PHP variables accessible anywhere.

• $_GET → collects form data via GET.

• $_POST → collects form data via POST.

• $_REQUEST → handles both GET and POST.

• $_SESSION → stores session data.

• $_COOKIE → stores client-side data.

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Q4. Explain the steps to create and manage a session in PHP.
Answer:

1. Start session using session_start();.

2. Store data → $_SESSION['user']="Jay";.

3. Access session variables on another page.

4. End session with session_destroy();.

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Q5. Why are sessions used in PHP applications?
Answer:
Sessions store user data across multiple pages. They are used for:

• Login systems (user authentication).

• Shopping carts in e-commerce.

• Tracking user preferences.

• Ensuring secure user interaction.