Input Validation for Web Forms CASENET Practice Questions (Page 6)

Questions 26–30

1. 26foundation · easy

   Which ASP.NET validation control is used when you need to implement complex validation logic that cannot be expressed with built-in validators?

   • ARegularExpressionValidator
   • BCustomValidator
   • CRangeValidator
   • DRequiredFieldValidator
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2. 27expert · hard

   A company is building a file upload feature for a web application. The requirements are: 1) Users can upload images only (JPEG, PNG, GIF). 2) The maximum file size is 5 MB. 3) The application must prevent malicious files from being uploaded. The team is debating between checking the file extension and checking the file content. Which approach should be implemented?

   • ACheck both the file extension and the file content (magic bytes) to ensure the file is a valid image.
   • BStore the file in a database as a BLOB and rely on the database to validate the file type.
   • COnly check the file extension because it is simpler and faster.
   • DOnly check the file content because extension checks are unnecessary.
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4. 28foundation · easy

   Which of the following is an important validation rule for file uploads to prevent malicious files?

   • AValidate the file size and content type.
   • BAllow all file types as long as the user is authenticated.
   • CCheck only the file extension.
   • DStore the file with its original filename.
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5. 29foundation · easy

   What is the primary purpose of output encoding when rendering user input in a web page?

   • ATo prevent the browser from interpreting user input as executable code.
   • BTo compress the data sent to the client.
   • CTo make the page load faster.
   • DTo store the data securely in the database.
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6. 30application · medium

   A web application has a form that allows users to enter a date of birth. The requirement is that the user must be at least 18 years old. The team is using a CustomValidator. Which code snippet should be used in the server-side validation function?

   • AUse a RegularExpressionValidator to match the date format and assume the user is an adult.
   • BUse a RangeValidator with MinimumValue set to the current date minus 18 years.
   • CParse the input as a DateTime, compare it with today's date minus 18 years, and set args.IsValid accordingly.
   • DCompare the input string with a hardcoded date string.
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