(Bar Chart Printing Program) One interesting application of computers is to display graphs and bar charts. Write an application that reads five numbers between 1 and \(30 .\) For each number that's read, your program should display the same number of adjacent asterisks. For example, if your program reads the number 7, it should display *******. Display the bars of asterisks after you read all five numbers.

When developing a Bar Chart Printing Program, it's essential to ensure that the inputs provided by the user are within the acceptable range. This process is referred to as input validation. It is the first step in safeguarding that the program behaves correctly. Validating input typically involves checking if the data falls within a specific set of criteria—in this case, whether the numbers are between 1 and 30.

Here's how to approach it: prompt the user to enter a number, and then utilize a conditional statement like an if-else block to verify the number's validity. If the number doesn’t meet the criteria, the user should be asked to re-enter a valid number. This step is pivotal as it prevents potential errors later in the program and ensures that the output - the bar chart - is displayed correctly and meaningfully.

To create the bar chart, our program requires user-provided numbers that will determine the lengths of the bars. The process of obtaining these numbers is known as reading user inputs. Typically, a concise prompt tells the user what they need to do, for instance: 'Enter a number between 1 and 30'.

For the Bar Chart Printing Program, a loop can be used to repeatedly ask for input until five valid numbers are collected. Each number is checked using input validation techniques before being stored in a data structure like an array or list. It's crucial to provide feedback to the user if the entered value is invalid and to only proceed when a valid number has been given.

The backbone of efficiently repeating tasks in programming is the use of looping constructs. In our bar chart program, loops are utilized in two key areas. First, to repeatedly request and validate user input until five valid numbers are collected. This is usually accomplished with a 'for' or 'while' loop.

Secondly, loops are employed to iterate through the collected numbers to display the appropriate number of asterisks. A 'for' loop is ideal for this because it iterates a known number of times - once for each element in the array, translating each numeric value to a corresponding number of asterisks, which in turn creates our bar chart.

Once we have our validated inputs, the last step of the program involves displaying output. In this context, the output is the visual representation of the bar chart made of asterisks. The number of asterisks corresponds to each number inputted by the user.

To display these 'bars', the program iterates over the stored numbers and for each, prints a line of asterisks equivalent to the number's value. This is typically done within a loop construct, which accesses each number and then uses another loop to print that number of asterisks. This process is repeated for each number. The result is a simple but effective graphical representation of the data - a vital aspect of data visualization.