1)
Class
C {
public static void main(String[]
args)
{
int[]a1[]=new int[3][3];
//3
int a2[4]={3,4,5,6}; //4
int a2[5]; //5
}
}
What
is the result of attempting to compile and run the program ?.
1.compiletime
error at lines 3,4,5
2.compiltime
error at line 4,5
3.compiletime
error at line 3
4.Runtime
Exception
5.None
of the above
Ans:
2
Explanation:
no
value shoud be specified in the rightsidebrackets when constructing an array
2)
interface
I
{
void f1(); // 1
public void f2(); // 2
protected void f3(); // 3
private void f4(); // 4
}
which
lines generate compile time errors?
1.compiletime
error at lines 1,2,3,4
2.compiletime
error at line 3
3.compiletime
error at line 1
4.compiletime
error at lines 3,4
5.None
of the above
Answer:
4
Explanation:
all
methods declared within an interface are implicitly public, a weaker access
level can not be declared.
3)
class
C{
int i;
public static void main (String[]
args) {
int i; //1
private int a = 1; //2
protected int b = 1; //3
public int c = 1; //4
System.out.println(a+b+c); //5
}}
1.compiletime
error at lines 1,2,3,4,5
2
compiletime error at lines 2,3,4,5
3.compiletime
error at lines 2,3,4
4.prints
3
5.None
of the above
Answer 2
Explanation:
The
access modifiers public, protected and private, can not be applied to variables
declared inside methods.
4)
Class
C {
public static void main (String[]
a1) {
System.out.print(a1[1] + a1[2] +
a1[3]);
}}
What
is the result of attempting to compile and run the program?
java
command A B C
1.Prints:
ABC
2.Prints
BC and Runtime Exception
3.Prints:
BCD
4.Runtime
Exception
5.None
of the above
Answer
2
Explanation:
array
index outof bounds exception only till a1[2] is allowed.
5)
class
C{
static int s;
public static void main(String a[]){
C obj=new C();
obj.m1();
System.out.println(s);
}
void
m1();
{
int x=1;
m2(x);
System.out.println(x+"");
}
void
m2(int x)
{
x=x*2;
s=x;
}
}
1.prints
1,2
2.prints
2,0
3.prints
2,2
4.compile
time error
5.Noneofthe
above
Answer:
1
Explanation:
Only
objects and arrays are passed by reference.other are passed by value.s is a
static variable which is global to the class
6)
class
C {
public static void main(String[]
args)
{
int i1=1;
switch(i1)
{
case 1:
System.out.println("one");
case 2:
System.out.println("two");
case 3:
System.out.println("three");
}}}
What
is the result of attempting to compile and run the program?
1.prints
one two three
2.prints
one
3.compile
time error
4.Runtime
exceptionf
5.None
of the above
Answer:
1
Explanation:
There
is no break statement in case 1 so it causes the below case statements to
execute regardless of their values
7)
Each element must be unique
Duplicate elements must not replace old
elements.
Elements are not key/value pairs.
Accessing an element can be almost as fast as
performing a similar operation on an array.
Which of these classes provide the specified
features?
1.LinkedList
2.TreeMap
3.HashMap
4.HashSet
5.None
of the above
Answer:
4
8)
class
C1
{
static interface I
{
static class C2
{
}
}
public
static void main(String a[])
{
C1.I.C2
ob1=new C1.I.C2();
System.out.println("object
created");
}
}
What
is the result of attempting to compile and run the program?
1.prints
object created
2.Compile
time error
3.Runtime
Excepion
4.None
of the above
Answer:
1
Explanation:
A
static interface or class can contain static members.Static members can be accessed
without instantiating the particular class
9)
class
C1
{
static
class C2
{
static int i1;
}
public
static void main(String a[])
{
System.out.println(C1.C2.i1);
}
}
What
is the result of attempting to compile and run the program?
1.prints
0
2.Compile
time error
3.Runtime
exception
4.None
of the above
Answer:
1
Explanation:
static
members can be accessed without instantiating the particular class
10)
A
signed data type has an equal number of non-zero positive and negative values
available
1.true
2.false
Answer:
2
Explanation:
The
range of negative numbers is greater by 1 than the range of positive numbers
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