Create a generic class Box with a type parameter that simulates drawing an item at random out of a box. This class could be used
for simulating a random drawing. For example, the box might contain Strings representing names written on a slip of paper, or the box might contain Integers representing a random drawing for a lottery based on numeric lottery picks. Create an add() method that allows the user of the class to add an object of the specified type along with size() and isEmpty() method. The former method returns the number of items in the box. Tha latter method determines whether or not the box is empty. Finally, your class should have a drawItem() method that randomly selects an object from the box and returns it (the item is removed from the box). If the user attempts to draw an item out of an empty box, return null. Note that we want the size of the box to be dynamic. In other words, there should not be a hard limit on the size of the box. The user can insert only a few or a large number of items. What is a good option here
1 answer:
Answer:
Check the explanation
Explanation:
//*********** Box.java *********
import java.util.ArrayList;
public class Box<T> {
ArrayList<T> items=new ArrayList<T>();
public void add(T item)
{
items.add(item);
}
public boolean isEmpty()
{
return items.isEmpty();
}
public T drawItem()
{
int randomIndex=(int)(Math.random()*items.size());
return items.get(randomIndex);
}
}
//*********** Driver.java *********
public class Driver {
public static void main(String args[])
{
Box<String> partners=new Box();
Box<Integer> hours=new Box();
String x="John";
String y="Tom";
String z="Annie";
partners.add(x);
partners.add(y);
partners.add(z);
hours.add(5);
hours.add(6);
hours.add(7);
hours.add(8);
hours.add(9);
hours.add(10);
String study_partner=partners.drawItem();
int study_hours=hours.drawItem();
System.out.println("Study partner: "+study_partner);
System.out.println(("Study hours: "+study_hours));
}
}
Kindly check the attached image below to see the output.
You might be interested in
Answer:
Here is the JAVA program:
import java.util.Scanner; // for taking input from user
//class to count number of times a character appears in the string
public class CharacterCounter
//method which returns number of times a character appear in string
{ public static int CountCharacter(String userString, char character)
{
int counter = 0; //stores the no of times character appears in string
for (int i=0; i<userString.length(); i++) //loop moves through entire string
{ // if character matches the character in the string
if (userString.charAt(i) == character)
counter++; // adds one to the character counter variable
}
return counter; } // returns no of time character is found in string
public static void main(String[] args) {
Scanner scanner = new Scanner(System. in);//takes input from user
String string;
char character;
System.out.println("Enter a string"); //prompts user to enter a string
string = scanner.nextLine(); //scans the input string
System.out.println("Enter a character");
// prompts user to enter character
character = scanner.next().charAt(0); //scans and reads the character
System.out.println("number of times character "+character + " appears in the string " + string +": " + CountCharacter(string, character)); } }
// calls CountCharacter method to output no of times a character appears in the input string
Explanation:
The method CountCharacter() has a loop in which the variable i works as an index which moves through each character of the string and if the character of the string in i matches the character which is to be found in the string then the value of counter variable increments by 1. This means that counter variable keeps counting the number of time the character appears in the string. The loop breaks when value of i exceeds the length of the string which means that the i reaches the end of the string and has searched the entire string for the specified character. In the end the count variable returns the number of time character appeared in the string. The main() function takes as input from the user, a string and a character to be searched for in the string. It then calls CountCharacter() function to find the number of times that input character appears in the input string and displays it on the output screen.
The program along with its output is attached as a screenshot.
