Pregunta 1
Pregunta
Which of the following statements are true?
Respuesta
-
An class is a blueprint for a object.
-
An object and a class are exactly the same.
-
An object is an instance of a class.
-
An attribute cannot be a reference to another object.
Pregunta 2
Pregunta
Given:
class X {
String str = "default";
X(String s) {
str = s;
}
void print() {
System.out.println(str);
}
public static void main(String[] args) {
new X("hello").print();
}
}
What is the result?
Pregunta 3
Pregunta
Which two will compile, and can be run successfully using the command: java Fred1 hello walls. (Choose two)
Respuesta
-
class Fred1{
public static void main (String args)
{ System.out.println(args[1]);}}
-
class Fred1{
public static void main (String [] args)
{ System.out.println(args[2]);}}
-
class Fred1 {
public static void main (String [] args)
{ System.out.println (args);}}
-
class Fred1 {
public static void main (String [] args)
{ System.out.println (args [1]);}}
Pregunta 4
Pregunta
Consider the following program:
class Point2D {
private int x, y;
public Point2D(int x, int y) {
x = x;
}
public String toString() {
return "[" + x + ", " + y + "]";
}
public static void main(String[] args) {
Point2D point = new Point2D(10, 20);
System.out.println(point);
}
}
Which one of the following options provides the output of this program when executed?
Respuesta
-
point
-
Point
-
[0, 0]
-
[10, 0]
-
[10, 20]
Pregunta 5
Pregunta
Which of the these are valid declarations of the main() method in the order to start the execution of a Java application?
Respuesta
-
static void main(String [] args){/* … */}
-
public static int main(String [] args){/*… */}
-
public static void main(String args){/*… */}
-
final public static void main(String [] arguments){/*… */}
-
public int main(String [] args, int argc){/*… */}
-
static public void main(String args []){/* … */}
Pregunta 6
Pregunta
Given:
public static void main(String[] args) {
double a = 2 + 5 * 6 / 7.0 % 6 + 7 - 9;
System.out.println(a);
}
What is the result?
Respuesta
-
-2.0
-
30.0
-
4.2857
-
compilation fails
Pregunta 7
Pregunta
What will be result of attempting to compile this class?
import java.util.*;
package test;
public class TestClass {
public OtherClass oc = new OtherClass();
}
class OtherClass {
int value;
}
Respuesta
-
The class will fail to compile, since the class OtherClass is used before it is defined.
-
There is no problem with the code.
-
The class will fail to compile, since the class OtherClass must be defined in a file called OtherClass.java
-
The class will fail to compile.
-
None of the above.
Pregunta 8
Pregunta
Given:
public class SuperLoop3 {
public static void main(String[] args) {
int suma = 0;
for (int i = 0, j = 9, z = 1; i < 4 && j > 0; i++, --j, j--) {
do {
suma += i * j % z + 3;
} while (z++ <= 1);
}
System.out.println("suma:: " + suma);
}
}
What is the result?
Respuesta
-
suma:: 22
-
suma:: 14
-
suma:: 20
-
compilation fails
Pregunta 9
Pregunta
Given:
class Test {
public static void main(String[] args) {
int var = 3;
switch (var) {
case 1:
try {
throw new IllegalArgumentException();
} catch (RuntimeException e) {
e.printStackTrace();
}
default:
try {
throw new ArrayIndexOutOfBoundsException();
} catch (RuntimeException e) {
e.printStackTrace();
}
case 2:
try {
throw new ArithmeticException();
} catch (RuntimeException e) {
e.printStackTrace();
}
}
}
}
What is the result?
Respuesta
-
java.lang.ArrayIndexOutOfBoundsException at com.bar.Test.main
and
java.lang.ArithmeticException at com.bar.Test.main at com.bar.Test.main
-
java.lang.ArrayIndexOutOfBoundsException at com.bar.Test.main
-
java.lang.ArithmeticException at com.bar.Test.main
-
compilation fails
Pregunta 10
Pregunta
Given:
public class Foo {
public static void main(String[] args) {
int a = 10;
long b = 20;
short c = 30;
System.out.println(++a + b++ * c);
}
}
Pregunta 11
Pregunta
class EJavaGuruStringBuilder {
public static void main(String args[]) {
StringBuilder ejg = new StringBuilder(10 + 2 + "SUN" + 4 + 5);
ejg.append(ejg.delete(3, 6));
System.out.println(ejg);
}
}
What is the output of the following code?
Respuesta
-
12S512S5
-
12S12S
-
1025102S
-
Runtime exception