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
Show Answer
Correct Answer: -32768 to 32767
Notes:
Answer: b
Explanation: Short occupies 16 bits in memory. Its range is from -32768 to 32767.
2). What is the range of byte data type in Java?
[A]-128 to 127
[B] -32768 to 32767
[C]-2147483648 to 2147483647
[D]None of the mentioned
Show Answer
Correct Answer: -128 to 127
Notes:
Answer: a
Explanation: Byte occupies 8 bits in memory. Its range is from -128 to 127
3). Which of the following are legal lines of Java code?
1. int w = (int)888.8;
2. byte x = (byte)100L;
3. long y = (byte)100;
4. byte z = (byte)100L;
[A]1 and 2
[B]2 and 3
[C]3 and 4
[D]All statements are correct
Show Answer
Correct Answer: All statements are correct
Notes:
Answer: d
Explanation: Statements (1), (2), (3), and (4) are correct. (1) is correct because when a floating-point number (a double in this case) is cast to an int, it simply loses the digits after the decimal. (2) and (4) are correct because a long can be cast into a byte. If the long is over 127, it loses its most significant (leftmost) bits. (3) actually works, even though a cast is not necessary, because a long can store a byte.
4). An expression involving byte, int, and literal numbers is promoted to which of these?
1. int w = (int)888.8;
2. byte x = (byte)100L;
3. long y = (byte)100;
4. byte z = (byte)100L;
[A]int
[B]long
[C]byte
[D]float
Show Answer
Correct Answer: int
Notes:
Answer: a
Explanation: An expression involving bytes, ints, shorts, literal numbers, the entire expression is promoted to int before any calculation is done.
5). Which of these literals can be contained in float data type variable?
1. int w = (int)888.8;
2. byte x = (byte)100L;
3. long y = (byte)100;
4. byte z = (byte)100L;
[A] -1.7e+308
[B] -3.4e+038
[C]+1.7e+308
[D]-3.4e+050
Show Answer
Correct Answer: -3.4e+038
Notes:
Answer: b
Explanation: Range of float data type is -(3.4e38) To +(3.4e38)
6). Which data type value is returned by all transcendental math functions?
1. int w = (int)888.8;
2. byte x = (byte)100L;
3. long y = (byte)100;
4. byte z = (byte)100L;
[A]int
[B]float
[C]double
[D]long
Show Answer
Correct Answer: double
Notes:
Answer: c
Explanation: Only double data type value is returned by all transcendental math functions. Transcendental math functions don’t return int or long. They return double instead of float as double has larger range.
7). What will be the output of the following Java code?
class average {
public static void main(String args[])
{
double num[] = {5.5, 10.1, 11, 12.8, 56.9, 2.5};
double result;
result = 0;
for (int i = 0; i < 6; ++i)
result = result + num[i];
System.out.print(result/6);
}
}
[A]16.34
[B]16.566666644
[C]16.46666666666667
[D]16.46666666666666
Show Answer
Correct Answer: 16.46666666666667
Notes:
Answer: c
Explanation: None.
output:
$ javac average.java
$ java average
16.46666666666667
8). What will be the output of the following Java statement?
class output {
public static void main(String args[])
{
double a, b,c;
a = 3.0/0;
b = 0/4.0;
c=0/0.0;
System.out.println(a);
System.out.println(b);
System.out.println(c);
}
}
[A]Infinity
[B]0.0
[C]NaN
[D]all of the mentioned
Show Answer
Correct Answer: all of the mentioned
Notes:
Answer: d
Explanation: For floating point literals, we have constant value to represent (10/0.0) infinity either positive or negative and also have NaN (not a number for undefined like 0/0.0), but for the integral type, we don’t have any constant that’s why we get an arithmetic exception.
9). What will be the output of the following Java code?
class increment {
public static void main(String args[])
{
int g = 3;
System.out.print(++g * 8);
}
}
Show Answer
Correct Answer: 32
Notes:
Answer: c
Explanation: Operator ++ has more preference than *, thus g becomes 4 and when multiplied by 8 gives 32.
output:
$ javac increment.java
$ java increment
32
10). What will be the output of the following Java code?
class area {
public static void main(String args[])
{
double r, pi, a;
r = 9.8;
pi = 3.14;
a = pi * r * r;
System.out.println(a);
}
}
[A]301.5656
[B]301
[C]301.56
[D]301.56560000
Show Answer
Correct Answer: 301.5656
Notes:
Answer: a
Explanation: None.
output:
$ javac area.java
$ java area
301.5656