Web Security: Common Vulnerabilities And Their Mitigation - Validating input

The video tutorial covers the importance of validating user input in web development, emphasizing security. It provides a detailed example of form validation using PHP, including error messaging and handling. The tutorial explains how to use PHP scripts to validate form inputs, focusing on regular expressions and PHP's filter functions for sanitizing and validating data.

Why is input validation crucial in web development?

• To enhance the website's visual appeal

• To prevent security breaches

• To ensure user satisfaction

• To increase website traffic

What is the main change in the form structure discussed in the video?

• Addition of a new field for middle name

• Removal of separate fields for first and last names

• Change in form submission method

• Inclusion of a CAPTCHA

How are error messages displayed next to input fields?

• Using JavaScript alerts

• By printing them in green text

• By sending an email to the user

• Through PHP variables echoed in the form

What is the first step in validating the name field?

• Checking if the name contains numbers

• Ensuring the name is not empty

• Converting the name to uppercase

• Verifying the name length

What function is used to match input against a pattern for validation?

• preg_match

• array_filter

• explode

• str_replace

What is the role of regular expressions in input validation?

• To format text

• To specify patterns for matching strings

• To generate random numbers

• To encrypt data

What PHP function is used to validate email formats?

• htmlspecialchars

• json_encode

• filter_var

• strtolower

Which flag is used with filter_var to validate integers?

• FILTER_SANITIZE_STRING

• FILTER_SANITIZE_NUMBER_INT

• FILTER_VALIDATE_EMAIL

• FILTER_VALIDATE_INT

What is the purpose of sanitizing input before validation?

• To increase input length

• To convert input to uppercase

• To remove or neutralize dangerous characters

• To make the input more readable

What does the filter_var function require to validate a variable?

• A regular expression

• A flag indicating the type of validation

• A database connection

• A user session