Assertions Questions and Answers

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Assertions questions with answers in Java programming test a candidate’s ability to debug and validate logic efficiently. The assert keyword is used to verify assumptions during program execution, ensuring code reliability and preventing logical errors. Many placement tests from companies like TCS, Infosys, and Wipro include Java Assertion MCQs to evaluate coding fundamentals. This section offers a collection of Java programming questions and answers with explanations to help you understand the use, syntax, and runtime behavior of assertions. Practice these questions to strengthen your programming logic and prepare effectively for technical interviews and coding tests.

Assertions

Showing 10 of 45 questions

11. When should assertions typically be used?

  • To validate user input
  • To check method parameters in public methods
  • For internal invariants and debugging assumptions
  • To handle file I/O errors
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12. What is the type of exception thrown by failed assertions?

  • AssertionException
  • RuntimeException
  • AssertionError
  • ValidationException
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13. Which command disables assertions?

  • -disableassertions or -da
  • -noassertions
  • -assertoff
  • -disableassert
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14. What happens if assertions are disabled?

  • Assert statements throw compile error
  • Assert statements are ignored at runtime
  • Program execution stops
  • All assertions return false
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15. Which Java version introduced assertions?

  • Java 1.0
  • Java 1.2
  • Java 1.4
  • Java 5
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16. What is the main advantage of using assertions over regular if-checks?

  • They provide better performance always
  • They can be enabled/disabled without code changes
  • They automatically handle exceptions
  • They work better with inheritance
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17. Which of these is NOT appropriate for assertions?

  • Checking internal class invariants
  • Validating user input in public methods
  • Checking control flow assumptions
  • Debugging complex calculations
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18. What will happen if you try to catch AssertionError?

  • Compilation error
  • Runtime exception
  • It can be caught but is not recommended
  • JVM crash
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19. Which package contains AssertionError?

  • java.util
  • java.lang
  • java.assert
  • java.error
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20. What is the output of: assert false : "Error message"; when assertions enabled?

  • Prints "Error message"
  • Throws AssertionError with "Error message"
  • Compilation error
  • No output
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