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Java Quiz Day 31
Question 1
Which of the following is a wrapper class for int in Java?
- A
Integer
- B
Int
- C
WrapperInt
- D
Number
Question 2
What is autoboxing in Java?
- A
Converting wrapper to primitive
- B
Manually wrapping a primitive
- C
Automatically converting primitive to wrapper
- D
Compiling boxed objects
Question 3
Which of these is NOT a valid wrapper class in Java?
- A
Integer
- B
Float
- C
Long
- D
String
Question 4
What is the output of the following code?
Integer a = 100;
int b = a;
System.out.println(b);
- A
0
- B
100
- C
Compilation error
- D
Runtime exception
Question 5
What is unboxing in Java?
- A
Wrapping primitive in object
- B
Converting object to class
- C
Converting wrapper to primitive
- D
Boxing a class
Question 6
Which of the following is true about wrapper classes?
- A
Wrapper classes allow primitives to be stored in collections
- B
Wrapper classes slow down performance
- C
Wrapper classes are used only in I/O
- D
Wrapper classes are deprecated
There are 6 questions to complete.