5432330
Pregunta 1
Pregunta
Only public and protected constructors are inherited from super class if the subclass is not in the same package.
Respuesta
- True
- False
Pregunta 2
Pregunta
Which constructor is valid in class BlaBla
Respuesta
-
BlaBla(BlaBla a)
-
private BlaBla()
-
public final BlaBla(int i)
-
public static BlaBla(char o)
Pregunta 3
Pregunta
Given the following code, which of these constructors can be added to class B without
causing a compile time error?
class A{
int i;
public A(int x) { this.i = x; }
}
class B extends A{
int j;
public B(int x, int y) {
super(x);
this.j = y;
}
}
Respuesta
-
B( ) { }
-
B(int y ) { j = y; }
-
B(int y ) { super(y*2 ); j = y; }
-
B(int y ) { i = y; j = y*2; }
-
B(int z ) { this(z, z); }
Pregunta 4
Pregunta
Consider the following array definitions:
int[] array1, array2[];
int[][] array3;
int[] array4[], array5[];
Which of the following are valid statements?
Respuesta
-
array2 = array3;
-
array2 = array4;
-
array1 = array2;
-
array4 = array1;
-
array5 = array3
Pregunta 5
Pregunta
What will be the result of trying to compile and execute of the following program?
public class TestClass{
public static void main(String args[] ){
int i = 0 ;
int[] iA = {10, 20} ;
iA[i] = i = 30 ;
System.out.println(""+ iA[ 0 ] + " " + iA[ 1 ] + " "+i) ;
}
}
Respuesta
-
It will throw ArrayIndexOutofBoundsException at Runtime.
-
Compile time Error.
-
It will prints 10 20 30
-
It will prints 30 20 30
-
It will prints 0 20 30
Pregunta 6
Pregunta
What will the following program print?
class Test{
public static void main(String[] args){
int i = 4;
int ia[][][] = new int[i][i = 3][i];
System.out.println( ia.length + ", " + ia[0].length+", "+ ia[0][0].length);
}
}
Respuesta
-
It will not compile.
-
3, 4, 3
-
3, 3, 3
-
4, 3, 4
-
4, 3, 3
Pregunta 7
Pregunta
Consider the following program...
class ArrayTest{
public static void main(String[] args){
int ia[][] = { {1, 2}, null };
for (int i = 0; i < 2; i++)
for (int j = 0; j < 2; j++)
System.out.println(ia[i][j]);
}
}
Which of the following statements are true?
Respuesta
-
It will not compile.
-
It will throw an ArrayIndexOutOfBoundsException at Runtime.
-
It will throw a NullPointerException at Runtime.
-
It will compile and run without throwing any exceptions.
-
None of the above.
Pregunta 8
Pregunta
Consider the following class...
class Test{
public static void main(String[ ] args){
int[] a = { 1, 2, 3, 4 };
int[] b = { 2, 3, 1, 0 };
System.out.println( a [ (a = b)[3] ] );
}
}
What will it print when compiled and run ?
Respuesta
-
It will not compile.
-
It will throw ArrayIndexOutOfBoundsException when run.
-
It will print 1.
-
It will print 3.
-
It will print 4
-
It will print 0
Pregunta 9
Pregunta
Given the following program, which statements are true?
// Filename: TestClass.java
public class TestClass{
public static void main(String args[]){
A[] a, a1;
B[] b;
a = new A[10]; a1 = a;
b = new B[20];
a = b; // 1
b = (B[]) a; // 2
b = (B[]) a1; // 3
}
}
class A { }
class B extends A { }
Respuesta
-
Compile time error at line 3.
-
The program will throw a java.lang.ClassCastException at the line labelled 2 when run.
-
The program will throw a java.lang.ClassCastException at the line labelled 3 when run.
-
The program will compile and run if the (B[ ] ) cast in the line 2 and the whole line 3 is removed.
Pregunta 10
Pregunta
Which of these statements are true?
Respuesta
-
If a RuntimeException is not caught, the method will terminate and normal execution of the thread will resume.
-
An overriding method must declare that it throws the same exception classes as the method it overrides.
-
The main method of a program can declare that it throws checked exceptions.
-
A method declaring that it throws a certain exception class may throw instances of any subclass of that exception class.
-
finally blocks are executed if and only if an exception gets thrown while inside the corresponding try block.
Pregunta 11
Pregunta
Consider the following code...
public class TestClass{
class MyException extends Exception {}
public void myMethod() throws XXXX{
throw new MyException();
}
}
Can we replace XXXX with MyException?
Respuesta
- True
- False
Pregunta 12
Pregunta
What will the following program print?
class Test{
public static void main(String[] args){
int i = 4;
int ia[][][] = new int[i][i = 3][i];
System.out.println( ia.length + ", " + ia[0].length+", "+ ia[0][0].length);
}
}
Respuesta
-
It will not compile.
-
3, 4, 3
-
3, 3, 3
-
4, 3, 4
-
4, 3, 3
Pregunta 13
Pregunta
What will the following code print ?
class Test{
public static void main(String[] args){
int k = 1;
int[] a = { 1 };
k += (k = 4) * (k + 2);
a[0] += (a[0] = 4) * (a[0] + 2);
System.out.println( k + " , " + a[0]);
}
}
Respuesta
-
It will not compile.
-
4 , 4
-
25 , 25
-
13 , 13
-
None of the above.
Pregunta 14
Pregunta
What will the following code print when compiled and run?
class Base{
void methodA(){
System.out.println("base - MethodA");
}
}
class Sub extends Base{
public void methodA(){
System.out.println("sub - MethodA");
}
public void methodB(){
System.out.println("sub - MethodB");
}
public static void main(String args[]){
Base b=new Sub(); //1
b.methodA(); //2
b.methodB(); //3
}
}
Respuesta
-
sub - MethodA and sub - MethodB
-
base - MethodA and sub - MethodB
-
Compile time error at //1
-
Compile time error at //2
-
Compile time error at //3
Pregunta 15
Pregunta
What will be printed?
class A1 {
static int i;
}
class A {
public static void main(String[] args) {
A1 a1 = null;
System.out.println(a1.i);
}
}
Respuesta
-
10
-
This code will not compile.
-
NullpointerException will be thrown
-
0
Pregunta 16
Pregunta
What will be the output of:
Short k = 9; Integer i = 9; System.out.println(k == i);
Please provide argumentation to your answer.
Respuesta
-
true
-
false
-
Compilation error
-
Exception in runtime
-
Other
Pregunta 17
Pregunta
Consider the following code:
class A{
public XXX m1(int a){
return a*10/4-30;
}
}
class A2 extends A{
public YYY m1(int a){
return a*10/4.0;
}
}
What can be substituted for XXX and YYY so that it can compile without any
problems?
Respuesta
-
int, int
-
int, double
-
double, double
-
double, int
-
Nothing, they are simply not compatible.
Pregunta 18
Pregunta
Consider the following code:
class A{
A() { print();
}
void print() { System.out.println("A"); }
}
class B extends A{
int i =
Math.round(3.5f);
public static void main(String[] args){
A a = new B();
a.print();
}
void print() { System.out.println(i); }
}
What will be the output when class B is run ?
Respuesta
-
It will print A, 4.
-
It will print A, A
-
It will print 0, 4
-
It will print 4, 4
-
None of the above.
Pregunta 19
Pregunta
Consider :
class A { public void perform_work(){} }
class B extends A { public void perform_work(){}
class C extends B { public void perform_work(){}
}
}
How can you let perform_work() method of A to be called from an instance method in C?
Respuesta
-
( (A) this ).perform_work( );
-
super.perform_work( );
-
super.super.perform_work( );
-
this.super.perform_work( );
-
It is not possible.
Pregunta 20
Pregunta
Expression (s instanceof java.util.Date) will return false if 's' was declared
as a variable of class java.lang.String .
Respuesta
- True
- False
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