Core Java Mock Test-3
INTRODUCTION TO OOPS INTRODUCTION TO JAVA AND SDE LANGUAGE FUNDAMENTALS AND OPERATORS
- 1.Consider the following code: 1. class Test { 2. public static void main(String args[]) { 3. double d = 12.3; 4. Dec dec = new Dec(); 5. dec.dec(d); 6. System.out.println(d); 7. } 8. } 9. class Dec{ 10. public void dec(double d) { d = d - 2.0d; } 11. } Which of the following gives the correct value printed at line 6?
- A.
Prints: 12.3
- B.
Prints: -2.0
- C.
Prints: 10.3
- D.
Prints: 0.0
- 2.Consider the following code: public class LabeledBreak2 { public static void main(String args[]) { loop: for(int j=0; j<2; j++) { for(int i=0; i<10; i++) { if(i == 5) break loop; System.out.print(i + " "); } } } } Which of the following will be the output for the above code?
- A.
0 1 2 3 4 5
- B.
Indefinite Loop
- C.
1 2 3 4 5
- D.
0 1 2 3 4
- E.
0 1 2 3 4 0 1 2 3 4
- 3.Consider the following scenario: Real Chocos Private Limited deals in manufacturing variety of chocolates. This organization manufactures three varieties of chocolates. 1. Fruit Chocolates 2. Rum Chocolates 3. Milk Chocolates A software system needs to be built. Which of the following options identifies the Classes and Objects?
- A.
Class: Real Chocos Private Limited Objects: Chocolate
- B.
Class: Chocolate Objects: Fruit Chocolates, Rum Chocolates, Milk Chocolates
- C.
Class: Chocolate Objects: Milk Chocolates
- D.
Class: Fruit Chocolates Objects: Rum Chocolates
- 4.Consider the following code: class A { } class B extends A { } public class Code2 { public void method(A a) { System.out.println("A"); } public void method(B b) { System.out.println("B"); } public static void main(String args[]) { new Code2().method(new Object()); } } Which of the following will be the output for the above code?
- A.
Throws ClassCastException at runtime
- B.
Prints: B
- C.
Compilation Error 'Cannot find the symbol'
- D.
Prints: A
- E.
Return this.name.hashCode() == a.name.hashCode();
- 5.Consider the following code: class Planet { } class Earth extends Planet { } public class WelcomePlanet { public static void welcomePlanet(Planet planet) { if (planet instanceof Earth) { System.out.println("Welcome!"); } else if (planet instanceof Planet) { System.out.println("Planet!"); } else { System.exit(0); } } public static void main(String args[]) { WelcomePlanet wp = new WelcomePlanet(); Planet planet = new Earth(); welcomePlanet(planet); } } Which of the following will be the output of the above program?
- A.
An exception is thrown at runtime
- B.
Planet!
- C.
The code runs with no output
- D.
Welcome!
- E.
Compilation fails
- 6.Consider the following code: public class Code13 { public static void main(String... args) { for(String s:args) System.out.print(s + ", "); System.out.println(args.length); } } Which of the following will be the output if the above code is attempted to compile and execute?
- A.
Program compiles successfully and prints the passed arguments as comma separated values and finally prints the length of the arguments-list
- B.
Runtime Error: NoSuchMethodError
- C.
Variable arguments cannot be used with enhanced for-loop
- D.
Compilation Error: var-args cannot be used as arguments for main() method
- 7.Consider the following code: class UT1 { static byte m1() { final char c = 'u0001'; return c; } static byte m3(final char c) { return c; } public static void main(String[] args) { char c = 'u0003'; System.out.print(""+m1()+m3(c)); } } Which of the following gives the valid output of the above code?
- A.
Compile-time error
- B.
Prints: 13
- C.
Run-time error
- D.
Prints: 4
- E.
None of the listed options
- 8.Which are all platform independent among the following? (Choose 3)
- A.
JAR Files
- B.
Java Virtual Machine (JVM)
- C.
Java Development Kit (JDK)
- D.
Java Class Files
- E.
Java Source Files
- 9.Consider the following partial code: public class CreditCard { private String cardID; private Integer limit; public String ownerName; public void setCardInformation(String cardID, String ownerName, Integer limit) { this.cardID = cardID; this.ownerName = ownerName; this.limit = limit; } } Which of the following statement is True regarding the above given code?
- A.
The class is fully encapsulated
- B.
The setCardInformation method breaks encapsulation
- C.
The code demonstrates polymorphism
- D.
The cardID and limit variables break polymorphism
- E.
The ownerName variable breaks encapsulation
- 10.Consider the following code: 1. public class DagRag { 2. public static void main(String [] args) { 3. 4. int [][] x = new int[2][4]; 5. 6. for(int y = 0; y < 2; y++) { 7. for(int z = 0; z < 4; z++) { 8. x[y][z] = z; 9. } 10. } 11. 12. dg: for(int g = 0; g < 2; g++) { 13. rg: for(int h = 0; h < 4; h++) { 14. System.out.println(x[g][h]); 15. 16. } 17. System.out.println("The end."); 18. 19. } 20. 21. } 22. } Which of the following code snippet when inserted at lines 15 and 18 respectively, will make the above program to generate the below output? 0 1 2 3 The end.
- A.
If(g==3) break rg; if(h==0) break dg;
- B.
If(h > 3) break dg; if(g > 0) break rg;
- C.
If(h==3) break rg; if(g==0) break dg;
- D.
If(h > 3) break dg; if(g > 0) break dg;
- 11.Consider the following code snippet: class Animal { String name; public boolean equals(Object o) { Animal a = (Animal) o; // Code Here } } class TestAnimal { public static void main(String args[]) { Animal a = new Animal(); a.name = "Dog"; Animal b = new Animal(); b.name = "dog"; System.out.println(a.equals(b)); } } Which of the following code snippets should be replaced for the comment line (//Code Here) in the above given code, to get the output as true?
- A.
Return this.name.equalsIgnoreCase(a.name);
- B.
Return this.name.equals(a.name);
- C.
Return super.equals(a);
- D.
Return this.name == a.name;
- 12.Consider the following code snippet: public class TestString9 { public static void main(String st[]){ String s1 = "java"; String s2 = "java"; String s3 = "JAVA"; s2.toUpperCase(); s3.toUpperCase(); boolean b1 = s1==s2; boolean b2 = s1==s3; System.out.print(b1); System.out.print(" "+b2); } } What will be the output of the above code snippet?
- A.
False true
- B.
True true
- C.
True false
- D.
Runtime error
- E.
false false
- 13.Consider the following code snippet: public class Welcome { String title; int value; public Welcome() { title += " Planet"; } public void Welcome() { System.out.println(title + " " + value); } public Welcome(int value) { this.value = value; title = "Welcome"; Welcome(); } public static void main(String args[]) { Welcome t = new Welcome(5); } } Which of the following option will be the output for the above code snippet?
- A.
Compilation fails
- B.
Welcome Planet 5
- C.
Welcome 5
- D.
Welcome Planet
- E.
The code runs with no output
- 14.Consider the following code: class ExampleFive { public static void main(String[] args) { final int i = 22; byte b = i; System.out.println(i + ", " + b); } } Which of the following gives the valid output for the above code?
- A.
Prints: 22, 20
- B.
Runtime Error: Cannot type cast int to byte
- C.
Prints: 22, 22
- D.
Compile Time Error: Loss of precision
- 15.Consider the following code snippet: class TestString2 { public static void main(String args[]) { String s1 = "Test1"; String s2 = "Test2"; s1.concat(s2); System.out.println(""+s1.charAt(s1.length() - 3) + s1.indexOf(s2)); } } What will be the output of the above code snippet?
- A.
S5
- B.
S-1
- C.
T4
- D.
15
- E.
T4
- 16.Consider the following code: 1. public class SwitchIt { 2. public static void main(String[] args) 3. int w1 = 1; 4. int w2 = 2; 5. System.out.println(getW1W2(w1, w2)); 6. } 7. 8. public static int getW1W2(int x, int y) { 9. switch (x) { 10. case 1: x = x + y; 11. case 2: x = x + y; 12. } 13. return x; 14. } 15. } Which of the following gives the valid output of above code?
- A.
Compilation succeeds and the program prints "5"
- B.
Compilation fails because of an error on line 9
- C.
Compilation succeeds and the program prints "3"
- D.
Compilation fails because of errors on lines 10 and 11
- 17.Consider the following code snippet: class Train { String name = "Shatapdhi"; } class TestTrain { public static void main(String a[]) { Train t = new Train(); System.out.println(t); // Line a System.out.println(t.toString()); // Line b } } Which of the following statements are true?(Choose 3)
- A.
Line a prints the corresponding classname with Object's hashcode in Hexadecimal
- B.
Both Line a and Line b prints "Shatapdhi"
- C.
Both Line a and Line b will print the corresponding classname with Object's hashcode in Hexa Decimal
- D.
Output of Line a and Line b will be different
- E.
Output of Line a and Line b will be same
- 18.Which of the following are true about inheritance?(Choose 3)
- A.
In an inheritance hierarchy, a subclass can also act as a super class
- B.
Inheritance enables adding new features and functionality to an existing class without modifying the existing class
- C.
Inheritance enables adding new features and functionality to an existing class without modifying the existing class
- D.
Inheritance is a kind of Encapsulation
- E.
Inheritance does not allow sharing data and methods among multiple classes
- 19.Consider the following code: 1 public class A { 2 public void m1() {System.out.print("A.m1, ");} 3 protected void m2() {System.out.print("A.m2, ");} 4 private void m3() {System.out.print("A.m3, ");} 5 void m4() {System.out.print("A.m4, ");} 6 7 public static void main(String[] args) { 8 A a = new A(); 9 a.m1(); 10 a.m2(); 11 a.m3(); 12 a.m4(); 13 } 14 } Which of the following gives the lines that need to be removed in order to compile and run the above code correctly?
- A.
Lines 10, 11
- B.
No need to comment any line. Will compile and run
- C.
Lines 10, 11 and 12
- D.
Line 11
- 20.Which of the following options gives the difference between == operator and equals() method?
- A.
Equals compares hash value and == compares character sequence
- B.
No difference;they are essentially the same
- C.
If equals() is true then == is also true
- D.
==compares object's memory address but equals character sequence
- E.
== works on numbers equals() works on characters
- 21.Which of the following classes is new to JDK 1.6?
- A.
Java.io.File
- B.
Java.io.Serializable
- C.
Java.io.FileFilter
- D.
Java.io.Console
- E.
Java.io.Externalizable
- 22.Which of the following statements are correct regarding Static Blocks?(Choose 3)
- A.
A class that have static block, should have the main() method defined in it
- B.
A class can have more than one static block
- C.
Static blocks are executed only once
- D.
Static blocks are executed before main() method
- E.
A static block can call other methods in a class
- 23.Which of the following flow control features does Java support? (Choose 2)
- A.
Labeled continue
- B.
Labeled goto
- C.
Labeled throw
- D.
Labeled catch
- E.
Labeled break
- 24.Which of the following options gives the relationship between a Spreadsheet Object and Cell Objects?
- A.
Polymorphism
- B.
Association
- C.
Aggregation
- D.
Inheritance
- E.
Persistence
- 25.Consider the following program: public class D extends Thread { public void run() { System.out.println("Before start method"); this.stop(); System.out.println("After stop method"); } public static void main(String[] args) { D a = new D(); a.start(); } } What will be the output of the above program?
- A.
'Before start method' and 'After stop method'
- B.
Compilation error
- C.
'Before start method' only
- D.
Runtime exception
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