14. Using Boolean Expressions

Answer:
Expression
Value
Expression
Value
25 == 25
true
25 != 25
false
25 <= 25
true
25 > 25
false
25 >= 25
true
25 = 25
illegal
-5 < 7
true
-305 <= 97
true

Using Boolean Expressions

In an if statement, the true or false  of a boolean expression picks whether the true branch or the false branch is executed. Look at another story problem:

A store wants a program that calculates the tax on an item of clothing. An item that costs $100 or more has a 5% tax. An item that costs less than $100 is tax free. Write a program that asks for a price, then calculates and prints the tax, then prints the total cost.

Here is the program, not quite finished:

 

public class TaxProgram
{
  public static void main (String[] args) 
  {
     
    
     
    
    double price;
    double tax ;

    System.out.println("Enter the price:");
    
          

    if (   )

         

    else
       

    System.out.println("Item cost: " + price + " Tax: " + tax + " Total: " + (price+tax) );    
  }
}

Here are some program fragments to use in completing the program. Use your mouse to copy-and-paste them into the program.

tax = price * taxRate;          Scanner scan = new Scanner( System.in );

price = scan.nextDouble();      final double taxRate = 0.05;

price >= 100.0                  import java.util.Scanner;

tax = 0.0;

(Of course, it would be nice to copy the program to a file, enter your corrections and run the program.)

Question 14:
Complete the program by filling in the blanks.