Question

Write a method minimum 3 that returns the smallest of three floating-point numbers. Use the Math.min method to implement minimum 3. Incorporate the method into an application that reads three values from the user, determines the smallest value and displays the result.

Short answer

Create `minimum3` using two `Math.min` calls, read user inputs, execute method, and display the smallest number.

Step-by-step solution

Define the minimum3 Method

Begin by defining a method named `minimum3` that receives three floating-point arguments. The purpose of this method is to return the smallest of these inputs. Importantly, this method will invoke the `Math.min` method twice to achieve this.

Implement minimum3 Using Math.min

Within the `minimum3` method, first use `Math.min` to find the smallest of the first two numbers. Then use `Math.min` again to compare the result with the third number. This way, `minimum3` will return the smallest number of all three inputs.

Develop the Application to Read User Input

Create an application that prompts the user to input three floating-point numbers. Use a scanner or similar method to read these values. Ensure the program is set up to handle floating-point numbers input by the user.

Call the minimum3 Method

With the user inputs received, call the `minimum3` method with these values as arguments. This will execute the comparison logic and return the smallest of the three values based on the computation done in `minimum3`.

Display the Result

Print the result returned by `minimum3` to the user. This final output will display the smallest of the three floating-point numbers input by the user.

Key concepts

Java Programming

Java is a popular, versatile, and widely-used programming language that is object-oriented. Its structure allows programmers to write reusable code and makes the process of developing complex applications easier. Java's syntax is similar to that of C++ but with fewer low-level facilities. One key feature of Java is its platform independence.
Thanks to the Java Virtual Machine (JVM), Java code can run on any device that has a JVM, without needing recompilation. This ability is often summarized by the phrase "write once, run anywhere." Java's extensive standard library provides a range of tools for developers, including utilities for input/output operations, networking, data structures, and more.

• Java programs are structured in classes and methods.
• The `main` method is the entry point of any Java application.
• Java has robust exception handling mechanisms.

These features, among others, make Java an ideal choice for developing secure, portable, and high-performance applications across various domains.

Method Implementation

Methods in Java are blocks of code that perform a specific task and can be called upon with a method name. They help break down complex problems into smaller, more manageable pieces. Implementing a method involves defining its signature, which includes its access modifiers, return type, method name, and parameters.
For example, to implement the `minimum3` method:

• Use the `public static` access modifiers.
• The return type should be `double` if working with floating-point numbers.
• Receive three parameters as input, which can be named `num1`, `num2`, and `num3`.

The `minimum3` method specifically utilizes the `Math.min` function to determine the smallest value among three floating-point numbers by comparing the first two numbers and then the result with the third number.
Careful method implementation improves code modularity, clarity, and reusability.

User Input Handling

Java provides various ways to handle user input, the most common being the `Scanner` class. This class allows programmers to read input from various sources, including the console. It is an essential tool for making interactive programs. The `Scanner` object is created with a reference to `System.in` to read user input from the standard input stream.
To handle user input in the application:

• Instantiate a `Scanner` object at the start of the program.
• Use methods like `nextDouble()` to read floating-point numbers.
• Always remember to handle potential exceptions, such as `InputMismatchException`, which occurs when the input does not match the expected type.

After processing the input, it's crucial to close the `Scanner` object with `close()` to free up resources. Handling user input correctly is vital for ensuring that applications can accommodate various input scenarios without failure.

Floating-Point Numbers

Floating-point numbers in Java represent fractional numbers and are used for precise calculations. They are defined using either the `float` or `double` keyword, with `double` being the default and more commonly used type due to higher precision.
Java's `double` data type supports approximately 15 decimal digits of precision, making it suitable for scientific calculations. It's important to understand that floating-point arithmetic can introduce rounding errors. As such, developers must be cautious when comparing floating-point numbers due to potential precision issues.

• Declare floating-point numbers with the `double` keyword for better precision.
• Be aware that `Math.min()` functions with `double` values return the smallest of the arguments while considering precision limits.
• Use formatting options like `DecimalFormat` if specific decimal precision display is needed.

By knowing how to handle floating-point numbers, developers can create reliable applications that handle real-number computations efficiently.