Question

Write a method squareOfAsterisks that displays a solid square (the same number of rows and columns) of asterisks whose side is specified in integer parameter side. For example, if side is 4, the method should display **** **** **** **** Incorporate this method into an application that reads an integer value for side from the user and outputs the asterisks with the squareOfAsterisks method.

Short answer

To create a square of asterisks, define a method squareOfAsterisks with an integer parameter side, use two nested loops to print asterisks in a square pattern, and create a main application to take user input for the side length and call the method.

Step-by-step solution

Define the method squareOfAsterisks

Begin by defining a method called squareOfAsterisks that takes one integer parameter, side, which represents the length of the sides of the square. This method will contain two nested loops; an outer loop that controls the number of rows and an inner loop that controls the number of columns.

Write the outer loop

Write the outer loop to iterate from 0 up to (but not including) the value of side. This will determine the number of lines (rows) that the square will have. Each iteration represents a single row of asterisks.

Write the inner loop inside the outer loop

Inside the body of the outer loop, write another loop (inner loop) that will also iterate from 0 up to (but not including) the value of side. This loop will print the asterisks for the current row without adding a new line at the end.

Print a newline after each row

After the inner loop completes (which means a full row of asterisks has been printed), print a newline character to move to the next line. This step is crucial to ensure that each row of asterisks will be on a separate line.

Create the main application

Write a main application (e.g., method or main class) that prompts the user to input an integer value. This will be the value passed to the squareOfAsterisks method as the side of the square.

Read user input

Use an input mechanism like a scanner (in Java) or equivalent in other languages to read the integer value entered by the user and store it in a variable.

Call squareOfAsterisks with the user input

Call the method squareOfAsterisks, passing the variable that holds the user input as an argument. This will print the square of asterisks to the screen.

Key concepts

Java Programming

At the core of Java programming is the ability to create and execute methods that perform specific tasks. In this context, the exercise is focused on implementing a method to print a square of asterisks. Java is known for being object-oriented, which means everything is associated with objects and classes. A Java program typically consists of many interacting objects that each contain data and operations, known as methods.

Methods, such as the squareOfAsterisks in the exercise, are fundamental to organizing Java programs. They allow us to encapsulate code into manageable blocks that can be easily tested, reused, and maintained. The exercise illustrates practical use of method declaration, control structures, user input through the Scanner class, and implementing nested loops within a method to achieve a specific pattern output. Following best practices, the method we implement should have a single responsibility: printing a square of asterisks based on the input provided.

Loop Control Structures

Control structures like loops allow Java programs to execute a block of code repeatedly. There are several types of loops available in Java, including for, while, and do-while loops. Nested loops, as utilized in our exercise, are a set of loops where one loop is placed inside another loop's body. They become particularly useful when dealing with multi-dimensional data structures or, as in our case, when we want to print a pattern.

In the squareOfAsterisks method implementation, the outer loop dictates how many rows of asterisks we print, while the inner loop focuses on the columns within each row. It's critical to manage loop counters carefully to ensure that loops run correctly and avoid common errors like infinite loops or off-by-one errors. Properly controlled nested loops are powerful tools that can solve complex problems efficiently by handling tasks that require multiple levels of iteration.

Method Implementation

Implementing a method involves defining its behavior and the parameters it will receive. In our exercise, the squareOfAsterisks method plays a significant role. The parameter side determines the size of the square, while the nested loops within the method generate the required output. The method signature, which includes the method's name, return type, and parameters, should be designed to clearly reflect its purpose.

The implementation should be seamless and understandable. For clarity, the inner loop that prints the asterisks does not include a newline character after each asterisk, which ensures they are printed on the same line, forming a row. After completing a row, a newline character is introduced to move to the next row. To maintain good encapsulation practice, separating the functionality of printing the square into its own method instead of directly writing it in the main method abstracts the complexity and allows the code to be reusable and more readable.