Objectives

To perform while (or do-while) loops.

To input a number until valid.

Prerequisites

Do this problem after you have completed the Conditional Expression programs and are ready to tackle simple while loops.

Description

Write a program (inRange.scala) that asks the user for two integers, A and B, and then asks the user for an integer within the range of A and B (inclusive). It should continue to ask the user for an integer until it is valid (within the range). If A is greater than B, the two numbers should be swapped (exchanged).

Sample Run

The following are some sample runs. It includes both input and output. For clarity, the input lines are preceded by the symbol > and the shell command (to start the program) is preceded by the symbol $. A sample input and output are separated afterwards.

$ scala inRange.scala Please enter two numbers defining the range. > 3 > 20 Please enter a number between 3 and 20. > 0 That number is not between 3 and 20. Please enter a number between 3 and 20. > -5 That number is not between 3 and 20. Please enter a number between 3 and 20. > 25 That number is not between 3 and 20. Please enter a number between 3 and 20. > 20 The number 20 is between 3 and 20. $ scala inRange.scala Please enter two numbers defining the range. > 45 > 15 Please enter a number between 15 and 45. > 10 That number is not between 15 and 45. Please enter a number between 15 and 45. > 50 That number is not between 15 and 45. Please enter a number between 15 and 45. > 30 The number 30 is between 15 and 45. 

Input

Here is just a sample input to the program.

3 20 0 -5 25 20 

Output

Here is just a sample output to the program. Notice that the prompts are part of the program's output.

Please enter two numbers defining the range. Please enter a number between 3 and 20. That number is not between 3 and 20. Please enter a number between 3 and 20. That number is not between 3 and 20. Please enter a number between 3 and 20. That number is not between 3 and 20. Please enter a number between 3 and 20. The number 20 is between 3 and 20. 

Hint

You will want to use the following Scala language features:

StdIn.readInt to read in integer values

if statement to check various conditions

while (or do-while) to repeat a sequence of statements while a condition is true (such as while the input is invalid).

need in scala