General Questions

Question 1 :

Which four options describe the correct default values for array elements of the types indicated?
1. int -> 0
2. String -> "null"
3. Dog -> null
4. char -> '\u0000'
5. float -> 0.0f
6. boolean -> true


A). 1, 2, 3, 4
B). 1, 3, 4, 5
C). 2, 4, 5, 6
D). 3, 4, 5, 6
Answer : Option B

Explanation :

(1), (3), (4), (5) are the correct statements.
(2) is wrong because the default value for a String (and any other object reference) is null, with no quotes.
(6) is wrong because the default value for boolean elements is false.


Question 2 :

Which one of these lists contains only Java programming language keywords?


A). class, if, void, long, Int, continue
B). goto, instanceof, native, finally, default, throws
C). try, virtual, throw, final, volatile, transient
D). strictfp, constant, super, implements, do
E). byte, break, assert, switch, include
Answer : Option B

Explanation :

All the words in option B are among the 49 Java keywords. Although goto reserved as a keyword in Java, goto is not used and has no function.
Option A is wrong because the keyword for the primitive int starts with a lowercase i.
Option C is wrong because "virtual" is a keyword in C++, but not Java.
Option D is wrong because "constant" is not a keyword. Constants in Java are marked static and final.
Option E is wrong because "include" is a keyword in C, but not in Java.


Question 3 :

Which will legally declare, construct, and initialize an array?


A). int [] myList = {"1", "2", "3"};
B). int [] myList = (5, 8, 2);
C). int myList [] [] = {4,9,7,0};
D). int myList [] = {4, 3, 7};
Answer : Option D

Explanation :

The only legal array declaration and assignment statement is Option D
Option A is wrong because it initializes an int array with String literals.
Option B is wrong because it use something other than curly braces for the initialization.
Option C is wrong because it provides initial values for only one dimension, although the declared array is a two-dimensional array.


Question 4 :

Which is a reserved word in the Java programming language?


A). method
B). native
C). subclasses
D). reference
E). array
Answer : Option B

Explanation :

The word "native" is a valid keyword, used to modify a method declaration.
Option A, D and E are not keywords. Option C is wrong because the keyword for subclassing in Java is extends, not 'subclasses'.


Question 5 :

Which is a valid keyword in java?


A). interface
B). string
C). Float
D). unsigned
Answer : Option A

Explanation :

interface is a valid keyword.
Option B is wrong because although "String" is a class type in Java, "string" is not a keyword.
Option C is wrong because "Float" is a class type. The keyword for the Java primitive is float.
Option D is wrong because "unsigned" is a keyword in C/C++ but not in Java.