PHP Forms Validate E-mail and URL

PHP Tutorial

📧🔗 PHP Form Validation – E-mail & URL

Validating email and URL inputs is essential to protect your application, ensure correct data, and avoid invalid submissions.
PHP provides built-in filters that make validation simple and reliable.

1️⃣ Why Validate E-mail & URL?

✔ Prevent invalid data
✔ Improve security
✔ Avoid broken links / wrong emails
✔ Mandatory in forms, login, registration, contact pages

2️⃣ PHP Filter Functions (Core Concept)

PHP uses filter_var() for validation.

Syntax

filter_var(value, filter_type);

Common filters:

  • FILTER_VALIDATE_EMAIL

  • FILTER_VALIDATE_URL

3️⃣ Validate E-mail in PHP ⭐

Basic Email Validation


 

✔ Accepts proper email format
❌ Rejects invalid emails like test@, test.com

4️⃣ Validate URL in PHP ⭐

Basic URL Validation


 

✔ Works for http, https, ftp

5️⃣ Complete PHP Form Example (Email + URL) ⭐⭐

form.php


 

PHP Validation Code


 

6️⃣ URL Validation with Required Scheme ⭐

Ensure URL contains http or https.



 

7️⃣ Optional: Sanitize Before Validation ⭐

Sanitization removes unwanted characters.

$email = filter_var($_POST['email'], FILTER_SANITIZE_EMAIL);
$url = filter_var($_POST['website'], FILTER_SANITIZE_URL);

📌 Best practice: Sanitize → Validate

8️⃣ Common Mistakes ❌

❌ Using regex instead of filters
❌ Skipping validation
❌ Trusting client-side validation only
❌ Not sanitizing input
❌ Accepting URLs without scheme unintentionally

9️⃣ Client-Side vs Server-Side Validation ⭐ (Interview)

Type JavaScript PHP
Speed Fast Slower
Security ❌ Weak ✔ Strong
Mandatory ❌ No ✔ Yes

📌 Always validate on server side (PHP)

📌 Interview Questions & MCQs (Very Important)

Q1. Which function is used for validation in PHP?

A) validate()
B) filter_var()
C) check_var()
D) is_valid()

✅ Answer: B

Q2. Which filter validates email?

A) FILTER_EMAIL
B) FILTER_CHECK_EMAIL
C) FILTER_VALIDATE_EMAIL
D) FILTER_SANITIZE_EMAIL

✅ Answer: C

Q3. Which filter validates URL?

A) FILTER_URL
B) FILTER_VALIDATE_URL
C) FILTER_CHECK_URL
D) FILTER_SANITIZE_URL

✅ Answer: B

Q4. Sanitization means?

A) Validation
B) Formatting
C) Removing unwanted characters
D) Encrypting data

✅ Answer: C

Q5. Which validation is mandatory?

A) Client-side
B) Server-side

✅ Answer: B

Q6. Best practice order?

A) Validate → Sanitize
B) Sanitize → Validate

✅ Answer: B

🔥 Real-Life Use Cases

✔ Registration forms
✔ Contact forms
✔ Newsletter signup
✔ Website submission forms
✔ User profile validation

✅ Summary

  • Use filter_var() for validation

  • FILTER_VALIDATE_EMAIL → email check

  • FILTER_VALIDATE_URL → URL check

  • Always sanitize input first

  • Server-side validation is mandatory

  • Very important for PHP exams & interviews

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