You have been given two classes, a Main.java and a Coin.java. The coin class represents a coin. Any object made from it will hav
e a 1) name, 2) weight and 3) value. As of now, the instance variables in Coin.java are all public, and the main function is calling these variables directly for the one coin made in it.
Required:
Your goal is to enforce information hiding principles in this tasl. Take Coin.java, make all instance variables private and create set/get functions for each instance variable. Then replace the direct references in main() to each instance variable with a call to an appropriate set or get function.
Required:
Your goal is to enforce information hiding principles in this tasl. Take Coin.java, make all instance variables private and create set/get functions for each instance variable. Then replace the direct references in main() to each instance variable with a call to an appropriate set or get function.
1 answer:
Answer:
Here is the Coin class:
public class Coin { //class names
private int value; // private member variable of type int of class Coin to store the value
private String coinName; // private member variable of type String of class Coin to store the coint name
private double weight; //private member variable of type double of class Coin to store the weight
public void setValue (int v) { //mutator method to set the value field
value = v; }
public void setName(String n){ //mutator method to set coinName field
coinName = n;}
public void setWeight (double w) { //mutator method to set weight field
weight = w; }
public int getValue () { //accessor method to get the value
return value; } // returns the current value
public String getName () { //accessor method to get the coin name
return coinName; } //returns the current coin name
public double getWeight () { //accessor method to get the weight
return weight; } } //returns the current weight
Explanation:
Here is the Main.java
public class Main{ //class name
public static void main(String[] args) { //start of main method
Coin penny = new Coin(); //creates object of Coin class called penny
penny.setName("Penny"); //calls setName method of Coin using object penny to set the coinName to Penny
penny.setValue(1); //calls setValue method of Coin using object penny to set the coin value to 1
penny.setWeight(0.003); //calls setWeight method of Coin using object penny to set the coin weight to 0.003
System.out.println("Coin name: " + penny.getName()); // calls getName method of Coin using penny object to get the current coin name stored in coinName field
System.out.println("Coin value: " + penny.getValue()); // calls getValue method of Coin using penny object to get the coin value stored in value field
System.out.println("Coin weight: " +penny.getWeight()); }} // calls getWeight method of Coin using penny object to get the coin weight stored in weight field
The value of coinName is set to Penny, that of value is set to 1 and that of weight is set to 0.003 using mutator method and then the accessor methods to access these values and prinln() to display these accessed values on output screen. Hence the output of the entire program is:
Coin name: Penny Coin value: 1 Coin weight: 0.003
The screenshot of the program along with its output is attached.
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Answer:
Following are the code to this question:
#include <iostream>//defining header file
#include <string.h>//defining header file
using namespace std;//using package
char checksum(const char *x)//defining a method checksum
{
int s=0,m,d;//defining integer variables
for (m= 1;*x;++x)//defining for loop for caLculate value
{
d=*x-'0';//use integer variable to remove last digit from input value
s=s+m*d;//add value in s variable
m=4-m;//use m to remove 4 from m
}
return '0'+(1000-s)%10;//use return keyword to get value
}
int main()//defining main method
{
char ISBNNum[14];// defining character array
cout<<"Enter the first 12 digits of an ISBN-13 as a string:";//print message
cin>>ISBNNum;//input value from user end
if(strlen(ISBNNum)==12)//defining if block to check length
{
char a=checksum(ISBNNum);//defining char variable a to call method checksum
ISBNNum[12]=a;//use array to hold method value
ISBNNum[13]='\0';// use array to hold 13 character value
cout<<"The ISBN-13 number is "<<ISBNNum;//print number
}
else//defining else block
{
cout<<ISBNNum<<" is an invalid input"<<endl;//print message
}
return 0;
}
output:
please find the attachment.
Explanation:
In the given code a character method "checksum" is define that accepts a character as a parameter and inside the method, three integer variable "s,m, and d" is defined that uses the for loop to calculate the input value and use the return keyword for the return value. Inside the main method, a char array "ISBNNum", is defined that input the value from the user-end and define the conditional statement.
- In the if block, it uses "ISBNNum" char array that checks its length equal to 12, if this condition is true it defines char a to call the method and hold its value and use the array to sore value in a and its 13 lengths it stores "\0", and print its value.
- If the condition is false, it will print input array value and print invalid input as a message.
Answer:
Following are the code to this question:
In option (i):
#include <iostream>//defining header file
using namespace std;
int findMax(int B[], int x)//defining recursive method findMax
{
if (x == 1)//defining condition when value of n==1
return B[0];//return array first element
return max(B[x-1], findMax(B, x-1)); // calling recursive method inside max method and return value
}
int main() //defining main method
{
int B[] = {12, 24, 55, 60, 50, 30, 29};//defining array B
int x= 7;//defining integer variable and assign a value
cout << "Maximum element value of the array is: "<<findMax(B, x)<<endl;//calling method findMax and print value
return 0;
}
Output:
Maximum element value of the array is: 60
In option (ii):
Explanation:
In the above-given program a recursive method "findMax" is defined, which accepts an array "B" and an integer variable "n" in its parameter, inside the method a conditional statement is used that, checks value of x equal to 1.
- If the above condition is true it will return the first element of the array and find the max number.
- Inside the main method, an array B is declared that assigns some values and an integer variable is declared, that also assigns some values, in the last step print method is used that pass value in method and prints its return value.
- In the option (ii) we calculate the Big-O notation algorithm value.