Java Language | 20 Minute‐Test 4


Instruction

  • Total number of questions : 20.
  • Time alloted : 20 minutes.
  • Each question carry 1 mark.
  • No Negative marks
  • DO NOT refresh the page.
  • All the best :-).

1.

What is the range of short data type in Java?

A.
-128 to 127
B.
-32768 to 32767
C.
-2147483648 to 2147483647
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

Short occupies 16 bits in memory. Its range is from -32768 to 32767.

2.

What is the numerical range of a char data type in Java?

A.
-128 to 127
B.
0 to 256
C.
0 to 32767
D.
0 to 65535

Your Answer: Option (Not Answered)

Correct Answer: Option D

Explanation:

Char occupies 16-bit in memory, so it supports 2^16 i:e from 0 to 65535.

3.

Which of these is long data type literal?

A.
0x99fffL
B.
ABCDEFG
C.
0x99fffa
D.
99671246

Your Answer: Option (Not Answered)

Correct Answer: Option A

Explanation:

Data type long literals are appended by an upper or lowercase L. 0x99fffL is hexadecimal long literal.

4.

Which of these is necessary condition for automatic type conversion in Java?

A.
The destination type is smaller than source type.
B.
The destination type is larger than source type.
C.
The destination type can be larger or smaller than source type.
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

None.

5.

Which of these operators is used to allocate memory to array variable in Java?

A.
malloc
B.
alloc
C.
new
D.
new malloc

Your Answer: Option (Not Answered)

Correct Answer: Option C

Explanation:

Operator new allocates block of memory specified by the size of array, and gives the reference of memory allocated to the array variable.

6.

Which of the following can be operands of arithmetic operators?

A.
Numeric
B.
Boolean
C.
Characters
D.
Both Numeric & Characters

Your Answer: Option (Not Answered)

Correct Answer: Option D

Explanation:

The operand of arithmetic operators can be any of numeric or character type, But not boolean.

7.

Which of these is not a bitwise operator?

A.
&
B.
&=
C.
|=
D.
<=

Your Answer: Option (Not Answered)

Correct Answer: Option D

Explanation:

<= is a relational operator.

8.

What is the output of relational operators?

A.
Integer
B.
Boolean
C.
Characters
D.
Double

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

None.

9.

Which of these have highest precedence?

A.
()
B.
++
C.
*
D.
>>

Your Answer: Option (Not Answered)

Correct Answer: Option A

Explanation:

Order of precedence is (highest to lowest) a -> b -> c -> d.

10.

Which of these selection statements test only for equality?

A.
if
B.
switch
C.
if & switch
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

switch statements checks for equality between the controlling variable and its constant cases.

11.

What is the stored in the object obj in following lines of code?
box obj;

A.
Memory address of allocated memory of object.
B.
NULL
C.
Any arbitrary pointer
D.
Garbage

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

Memory is allocated to an object using new operator. box obj; just declares a reference to object, no memory is allocated to it hence it points to NULL.

12.

What is the return type of a method that does not returns any value?

A.
int
B.
float
C.
void
D.
double

Your Answer: Option (Not Answered)

Correct Answer: Option C

Explanation:

Return type of an method must be made void if it is not returning any value.

13.

What is the return type of Constructors?

A.
int
B.
float
C.
void
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option D

Explanation:

Constructors does not have any return type, not even void.

14.

What is process of defining two or more methods within same class that have same name but different parameters declaration?

A.
method overloading
B.
method overriding
C.
method hiding
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option A

Explanation:

Two or more methods can have same name as long as their parameters declaration is different, the methods are said to be overloaded and process is called method overloading. Method overloading is a way by which Java implements polymorphism.

15.

Which of these access specifiers must be used for main() method?

A.
private
B.
public
C.
protected
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

main() method must be specified public as it called by Java run time system, outside of the program. If no access specifier is used then by default member is public within its own package & cannot be accessed by Java run time system.

16.

Arrays in Java are implemented as?

A.
class
B.
object
C.
variable
D.
None of the mentioned

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

None.

17.

String in Java is a?

A.
class
B.
object
C.
variable
D.
character array

Your Answer: Option (Not Answered)

Correct Answer: Option A

Explanation:

None.

18.

Which of these keyword must be used to inherit a class?

A.
super
B.
this
C.
extent
D.
extends

Your Answer: Option (Not Answered)

Correct Answer: Option D

Explanation:

None.

19.

Which of these keyword can be used in subclass to call the constructor of superclass?

A.
super
B.
this
C.
extent
D.
extends

Your Answer: Option (Not Answered)

Correct Answer: Option A

Explanation:

None.

20.

Which of these class is superclass of every class in Java?

A.
String class
B.
Object class
C.
Abstract class
D.
ArrayList class

Your Answer: Option (Not Answered)

Correct Answer: Option B

Explanation:

Object class is superclass of every class in Java.

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