Wrapper Classes
16.What is the result of unboxing?
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A. Object becomes primitive
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B. Primitive becomes Object
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C. NullPointerException always
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D. Compilation error
Object becomes primitive
Object becomes primitive
17.What will the following code display?
Integer x = 200;
Integer y = 200;
System.out.println(x == y);
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A. true
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B. false
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C. Error
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D. null
false
false
18.What is the output?
Boolean b1 = Boolean.valueOf("true");
Boolean b2 = Boolean.valueOf("false");
System.out.println(b1 + " " + b2);
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A. false false
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B. true false
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C. false true
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D. true true
true false
true false
19.Which of the following is NOT a valid wrapper class method?
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A. parseBoolean(String)
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B. toString()
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C. toInt()
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D. doubleValue()
toInt()
toInt()