Optional Class
1.What is the primary purpose of the Optional class in Java?
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A. To replace if-else statements for all conditional logic.
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B. To handle NullPointerException gracefully by providing a container for potentially null values.
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C. To optimize memory usage for large collections.
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D. To provide a new type of collection for storing elements.
To handle NullPointerException gracefully by providing a container for potentially null values.
To handle NullPointerException gracefully by providing a container for potentially null values.
2.Which method is used to create an Optional containing a non-null value?
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A. Optional.empty()
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B. Optional.ofNullable()
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C. Optional.of()
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D. Optional.create()
Optional.of()
Optional.of()
3.If an Optional object contains no value, what will get() method throw?
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A. NullPointerException
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B. NoSuchElementException
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C. IllegalStateException
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D. IllegalArgumentException
NoSuchElementException
NoSuchElementException
4.Which method can be used to provide a default value if the Optional is empty?
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A. get()
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B. isPresent()
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C. orElse()
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D. ifPresent()
orElse()
orElse()
5.What is the result of Optional.of("hello").isPresent()?
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A. true
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B. false
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C. null
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D. Compilation error
true
true