Boolean Expressions

This chapter introduces relational and logical operators. It also discusses the use of these operators to write Boolean expressions.

9. Range Testing


A 30 year old with $10000 credit could rent a car.
    age >= 21 && credit >= 10000 --------- --------------- true true ---------------- true

Range Testing

Frequently you need to test if a number is within a certain range.

A welter weight boxer must weight between 136 and 147 pounds. A boxer's weight is tested before each fight to be sure that he is within his weight category. Here is a program that checks if a welter weight boxer's weight is within range:

// Ringside Weigh-in
// Boxer must weigh between 136 and 147 pounds
import java.util.Scanner; public class Ringside
public static void main (String[] args)
Scanner scan = new Scanner( );
int weight; // get the weight
System.out.print("How heavy is the boxer? ");
weight = scan.nextInt(); // check that the weight is within range
if ( )
System.out.println("In range!" );
System.out.println("Out of range." );

Question 9:

Fill the blank so that weight is tested in two ways:

    1. weight must be equal or greater than 136
    2. weight must be less than or equal to 147