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PROBLEM SOLVING AND PYTHON PROGRAMMING QUIZ

1) What is the first step in problem-solving? A) Writing code B) Debugging C) Understanding the problem D) Optimizing the solution Answer: C 2) Which of these is not a step in the problem-solving process? A) Algorithm development B) Problem analysis C) Random guessing D) Testing and debugging Answer: C 3) What is an algorithm? A) A high-level programming language B) A step-by-step procedure to solve a problem C) A flowchart D) A data structure Answer: B 4) Which of these is the simplest data structure for representing a sequence of elements? A) Dictionary B) List C) Set D) Tuple Answer: B 5) What does a flowchart represent? A) Errors in a program B) A graphical representation of an algorithm C) The final solution to a problem D) A set of Python modules Answer: B 6) What is pseudocode? A) Code written in Python B) Fake code written for fun C) An informal high-level description of an algorithm D) A tool for testing code Answer: C 7) Which of the following tools is NOT commonly used in pr...

Java important Question - 5

Q) What are wrapper classes? Why do we need wrapper classes ?
Answer :
          Wrapper class provides the mechanism to convert primitive into object and object into primitive. In the java.lang package java provides a separate class for each of the primitive data types namely Boolean, Byte, Short, Integer, Float, Long, Double & Character. These are known as wrapper classes because they wrap the primitive data type into an object of the class.

Need of wrapper classes :
* They convert primitive data types into objects. Objects are needed if we wish to modify the arguments passed into a method.
* The classes in java.util package handles only objects and hence wrapper classes help in this case also.
* Data structures in the collection framework, such as ArrayList and vector, store only objects and not primitive types.
* An object is needed to support synchronization in multithreading.


Q) What is an interface ?
Answer :
          An interface is a reference type in Java. It is similar to class. It is a blueprint of a class. Interfaces specify what a class must do not how.
          An interface can have methods and variables like the class but the methods declared in interface are by default abstract. The class that implements interface must implement all the methods of that interface. Also, the variables declared in an interface are public, static and final by default.
          The interface keyword is used to declare an interface. Following is an example of an interface.

/* File name : NameOfInterface.java */
import java.lang.*;
// Any number of import statement
 
public interface NameOfInterface {
// Any number of final, static fields
// Any number of abstract method declarations
}

Q) What is an abstract class ?
Answer :
          Abstract classes are used in java to create a class with some default method implementation for subclasses. An abstract class can have abstract method without body and it can have methods with implementation also.
          abstract keyword is used to create a abstract class. Abstract classes can't be instantiated are mostly used to provide base for subclasses to extend and implement the abstract methods and override or use the implemented methods in abstract class.
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