PHP Forms Validate E-mail and URL

PHP Forms Validate E-mail and URL

In PHP Forms Validate E-mail 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.

Why Validate E-mail & URL?

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

PHP Filter Functions (Core Concept)

PHP uses filter_var() for validation.

Syntax

Common filters:

FILTER_VALIDATE_EMAIL
FILTER_VALIDATE_URL

Validate E-mail in PHP

Basic Email Validation

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

Validate URL in PHP

Basic URL Validation

Works for http, https, ftp

Complete PHP Form Example (Email + URL)

`form.php`

PHP Validation Code

<?php
if (isset($_POST['submit'])) {$email = $_POST['email'];
$website = $_POST['website'];

// Email validation
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
echo " Invalid Email<br>";
} else {
echo " Valid Email<br>";
}

// URL validation
if (!filter_var($website, FILTER_VALIDATE_URL)) {
echo " Invalid URL<br>";
} else {
echo "Valid URL<br>";
}
}
?>

<?php

if (isset($_POST['submit'])) {$email = $_POST['email'];

$website = $_POST['website'];

// Email validation

if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {

echo " Invalid Email<br>";

} else {

echo " Valid Email<br>";

}

// URL validation

if (!filter_var($website, FILTER_VALIDATE_URL)) {

echo " Invalid URL<br>";

} else {

echo "Valid URL<br>";

}

URL Validation with Required Scheme

Ensure URL contains http or https.

Optional: Sanitize Before Validation

Sanitization removes unwanted characters.

Best practice: Sanitize → Validate

Common Mistakes

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

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

PHP Forms Validate E-mail and URL