Take Input in Java using Scanner Class with Code

Taking user input is a fundamental aspect of programming that allows applications to interact with users. In Java, there are several ways to capture user input, but the most common method is using the Scanner class from the java.util package. This article will guide you through how to use the Scanner class to take input from users, complete with code examples and expected outputs.

Using the Scanner Class in Java

To use the Scanner class for user input, follow these steps:

• Import the Scanner Class: You need to import the java.util.Scanner package at the beginning of your program.
• Create a Scanner Object: Instantiate a Scanner object that reads from System.in, which is the standard input stream.
• Use Scanner Methods: Utilize various methods provided by the Scanner class to read different types of input (e.g., strings, integers, doubles).

Example Code

Here’s a simple Java program that demonstrates how to take different types of user input using the Scanner class:

import java.util.Scanner; // Step 1: Import the Scanner class

public class UserInputExample {
    public static void main(String[] args) {
        // Step 2: Create a Scanner object
        Scanner scanner = new Scanner(System.in);

        // Prompt for and read a string input
        System.out.print("Enter your name: ");
        String name = scanner.nextLine(); // Read user input as a string

        // Prompt for and read an integer input
        System.out.print("Enter your age: ");
        int age = scanner.nextInt(); // Read user input as an integer

        // Prompt for and read a double input
        System.out.print("Enter your salary: ");
        double salary = scanner.nextDouble(); // Read user input as a double

        // Output the collected inputs
        System.out.println("Hello, " + name + "!");
        System.out.println("You are " + age + " years old.");
        System.out.println("Your salary is $" + salary);

        // Close the scanner
        scanner.close();
    }
}

Explanation of Code

Importing Scanner: The line import java.util.Scanner; imports the Scanner class, making it available for use in your program.

Creating a Scanner Object: The statement Scanner scanner = new Scanner(System.in); creates a new instance of the Scanner class that reads input from the console.

Reading Input

• The method nextLine() reads an entire line of text (string).
• The method nextInt() reads an integer value.
• The method nextDouble() reads a double value.

Outputting Results: The collected inputs are printed back to the console.

Expected Output

When you run this program, it will prompt you for your name, age, and salary and then display them:

Conclusion

Using the Scanner class in Java provides a straightforward way to gather user input for your applications. By following this guide and utilizing the provided code example, you can effectively implement user input functionality in your Java programs. As you become more familiar with Java, you'll find that capturing user input can significantly enhance interactivity and usability in your applications.