Question

I need the following java code commented

import java.util.Scanner;

public class Main {

public static void main(String[] args) {
Scanner input = new Scanner (System.in);
int productNo=0;
double product1;
double product2;
double product3;
double product4;
double product5;
int quantity;
double totalsales=0;

while(productNo !=0)
System.out.println("Enter Product Number 1-5");
productNo=input.nextInt();

System.out.println("Enter Quantity Sold");
quantity=input.nextInt();

switch (productNo) {

case 1:
product1=1.00;
totalsales+=(1.00*quantity);
break;

case 2:
product2=2.00;
totalsales+=(2.00*quantity);
break;

case 3:
product3=6.00;
totalsales+=(6.00*quantity);
break;

case 4:
product4=23.00;
totalsales+=(23.00*quantity);
break;

case 5:
product5=17.00;
totalsales+=(17.00*quantity);
break;
  
}
  
System.out.println(totalsales);

}
}

Answer 1

Please find below the code with comments and also please find below the code screenshot to understand the indentation.

Commented Code

//importing scanner class from util
//using scanner to get the input from user
import java.util.Scanner;

//create class Main
public class Main {

//Create Main class method
public static void main(String[] args) {
  
//create scanner class object "input"
//using it to get the input from user
Scanner input = new Scanner (System.in);
//declare integer variable productNo
//assigned 0 to productNo
int productNo=0;
//declare double variable product1
double product1;
//declare double variable product2
double product2;
//declare double variable product3
double product3;
//declare double variable product4
double product4;
//declare double variable product5
double product5;
//declare integer variable quantity
int quantity;
////declare double variable totalsales
//assigned 0 to totalsales
double totalsales=0;
  
//while loop
//runs untill productno has a value not equal to 0
while(productNo !=0)
System.out.println("Enter Product Number 1-5");
//using scanner class object "input"
//to get the integer input from user using input.nextInt
//and assign the input value to productNo
productNo=input.nextInt();
//prints Enter Quantity sold to console
System.out.println("Enter Quantity Sold");
//using scanner class object "input"
//to get the integer input from user using input.nextInt
//and assign the input value quantity
quantity=input.nextInt();
  
  
//Switch Statement
//contains productNo as expression in switch
//runs for different cases
switch (productNo)
{
//Case statement
//if productNo is given input value as 1
//case 1 will be executed
case 1:
//product1 is assigned double value 1.00
product1=1.00;
//calculating totalsales
//multiplying 1 with quantity given as input
//and adding the multiplication result with totalsales
totalsales+=(1.00*quantity);
//break Statement
//to come out of switch
break;
  
//Case statement
//if productNo is given input value as 2
//case 2 will be executed
case 2:
//product2 is assigned double value 2.00
product2=2.00;
//calculating totalsales
//multiplying 2 with quantity given as input
//and adding the multiplication result with totalsales
totalsales+=(2.00*quantity);
//break Statement
//to come out of switch
break;
//Case statement
//if productNo is given input value as 3
//case 3 will be executed
case 3:
//product3 is assigned double value 6.00
product3=6.00;
//calculating totalsales
//multiplying 6 with quantity given as input
//and adding the multiplication result with totalsales
totalsales+=(6.00*quantity);
//break Statement
//to come out of switch
break;
//Case statement
//if productNo is given input value as 4
//case 4 will be executed
case 4:
//product4 is assigned double value 23.00
product4=23.00;
//calculating totalsales
//multiplying 23 with quantity given as input
//and adding the multiplication result with totalsales
totalsales+=(23.00*quantity);
//break Statement
//to come out of switch
break;
//Case statement
//if productNo is given input value as 5
//case 5 will be executed
case 5:
//product5 is assigned double value 17.00
product5=17.00;
//calculating totalsales
//multiplying 17 with quantity given as input
//and adding the multiplication result with totalsales
totalsales+=(17.00*quantity);
//break Statement
//to come out of switch
break;
  
}
  
//prints total sales calculated obove in switch Statement
//on the console
System.out.println(totalsales);

}
}

Code Screenshot