Programming in JAVA — DU B. Voc – Software Development Previous Year Question Papers

Specify the following statements are True/False. 5 i. Java supports multiple inheritance through classes. ii. The superclass of all classes in Java is Object ili. The main() method in Java can be overloaded. iv. Method overloading can be achieved by changing only the return type of a method. v. AWT is heavy weight and SWING is light weight. 3 a) What will be the output of following codes: class Vehicle ( String type = "4W"; int maxSpeed = 100; Vehicle (String type, int maxSpeed) { this.type = type; this.maxSpeed = maxSpeed; class Car extends Vehicle ( String trans; Car(String trans) { // line n1 this.trans = trans; Car(String type, int maxSpeed, String trans) { super(type, maxSpeed); // line n2 this.trans = trans; And given the code fragment: Car c1 = new Car("Auto"); Car c2 = new Car("4W", 150, "Manual"); System.out.printin(c1.type + " " + c1.maxSpeed + " " + c1.trans); System.out.printIn(c2.type +" " + c2.maxSpeed + ""+ c2.trans); What is the result? public static void main(String] args) { StringBuilder sb = new StringBuilder("Java"); String s = "Java"; if (sb.toString().equals(s.toString())) ( System.out.printin("Match 1"); else if (sb.equals(s)) | System.out.printin("Match 2"); System.out.printin("No Match"); What is the result? public class Test public int aMethodi) static int i = 0; itt; return i; public static void main(String argsi]) Test test = new Test(); test.aMethod(); int j = test.aMethod(); System.out.printin(j); b) Write a Java program that demonstrates how multiple constructors are executed when 5 objects are created with different arguments. 4 a) What is the difference between built-in and user-defined packages in Java? Write a Java 10 program to create a package student containing a class Student with attributes (name, roll number, marks) and a method to display the details. Use this package in another program. b) Write a Java program that performs the following string operations: 5 i. Reverses a given string. Converts the string to uppercase and lowercase. Differentiate between method overloading and method overriding. Write a Java program 10 where a base class Animal has a method sound), and a derived class Dog overrides the method. Also, demonstrate method overloading by defining two versions of the soundi) method (one that takes no parameters and one that takes an integer parameter). Describe the use of following keywords in java with code snippet (any two): 5 i. Super ii. Break ili. Swings iv. Abstract 6 a) Which Inheritance Is not supported by JAVA. How that unsupported inheritance can be 10 attained indirectly? Write a program for the same. program should accept user input and handle the following exceptions using appropriate try-catch blocks: Null Pointer Exception (when accessing methods on a null object) String Index Out Of Bounds Exception (when accessing an invalid index in a string) Input Mismatch Exception (when the user enters input of the wrong data type)